How can our (30f, 43m) relationship survive this potential depression?

I don't really know what to do or where to go from here but would really, really appreciate some advice or any outside perspective. I'm sorry for the long post but I really need help.

I (30f) started dating my partner, M (43m) about a year ago. We met when we were both in school. Throughout the last year, he's been there for me in ways that no one else ever has been and has let me be open in a way I've never experienced. He's been with me through some heavy depressive episodes which included self harm and suicidal ideation/urges; medication changes that have taken their toll on our relationship; revelations and big moments during therapy; new diagnoses; being on sick leave from work for my mental health; dropping out of school and postponing it for a year. He's literally been this rock for this last year and I don't know how I would have survived it without him. I am forever grateful for him and what he's done for me. Despite all of this going on, this last year has truly been amazing with him and has undoubtedly changed my life. I've experienced so many new things with him and felt a love I've never had before.

I have personally dealt with mental health struggles for most of my life and have had a LOT of family members and friends that have struggled, too. This isn't new to me. But I don't know how to help M.

A quick background on M - he also struggles with his mental health (depression and anxiety that have been medicated and under control for a couple of years). He has three kids and he's been separated from his ex-wife since before we started seeing each other. It's been a huge fight with her this last year as she very clearly struggles with some kind of mental illness (she sounds super paranoid all the time and is clearly not okay); she harasses and threatens him, withholds his kids from him, is demanding of things that he cannot and should not have to give to her. This has all been taking its toll on him and I think it's been slowly wearing him down. He's finally just recently started looking into getting a lawyer and going about the divorce this way (he thought before that they could do it amicably but she's shown that that's not going to happen). It's obviously taken its toll on him. He also started a new career this year that he absolutely loves. There have been lots of big changes for him.

M has seemed off for a little while now (maybe around a month?). I've noticed it and have brought it up a few times but it's not something we've seriously gotten into. I brought it up again about two weeks ago and just briefly touched on how I didn't know what was going on - if it was everything with work, his ex-wife, if he was feeling more depressed. We kind of spoke about it again but nothing too deep. However, we hung out Saturday and that's when everything finally came out and he realized how he's been feeling.

He said that he's felt more like a friend lately, that he knows he's been distancing himself from me but that it hasn't had an impact so he didn't really acknowledge it. I told him that it did have an impact and told him how I viewed how things have been lately - how he doesn't really talk to me anymore; I don't know what's going on in his life; I asked him over to make dinner together Saturday (the same night of this conversation) and on our way back to my place he was saying how he might just drop me off and go home to lay down instead (he obviously came in to hang out though, which is when we started talking); that I have to pry to get any kind of basic information out of him; that I ask him to hang out or spend the night together and he just ignores it; how he used to want to be around me all the time and it's like he doesn't want to be anymore; that I know how often he's on his phone and I'll text him but he just won't reply. I told him that I haven't felt this unwanted in a relationship and that it was hard (and I know that this all was probably selfish of me to say and put out there but I obviously didn't know where the conversation was going).

He felt really bad about everything and apologized, then replied. He said that he knows he wants to be around me and misses me & thinks about me when we're not together but feels like it's safer to just stay at his place in his room. He also said that when we are together, things feel like normal/fine and we're okay. He's afraid of letting me in and me seeing how he is and how bad things might get. He's scared of being fully open with me and scared of what might happen with the divorce. He acknowledged how hypocritical everything sounded because during all of my episodes this last year, I tried pushing him away and he told me not to/wouldn't let me, saying that he wanted to be here through it all and see me/be with me, even at my worst. He said that I don't deserve this version of him, that it's not fair and I should have the good side. He said that when he just put everything together, it made sense to be alone but that he knew it was fear based and that it felt wrong to listen to that. The more he explained things, the more it sounded like he was depressed. Before I could comment on that, he said that he was just realising that it sounded like it might be depression. It felt like this lightbulb kind of moment.

I told M that if he really wanted to go, he could go. I wouldn't hold him back; I wouldn't fight him or try to stop him because I obviously want him to be happy. But if this is depression and that's the depression talking, that I didn't think it was a good idea and that I wouldn't feel good just letting him go like that. I don't think it would be the best thing to be alone during all of that. I reassured him again that I didn't care about how bad things could get or what might be coming, that I want to be there for everything. I love every part of him and want to be there for every part of him. I told him that he doesn't get to decide what's best for me or what I deserve; that those are my choices to make - that I've chosen him every day this last year, I'm choosing him now and continue to choose him.

He used to see a therapist but stopped seeing her in probably September/October 2025. He pulled his phone out during the conversation to make an appointment with her. He said that he wants to start going back to therapy and see where that gets him and that he doesn't actually want to leave me. And I encouraged him to do that and maybe even speak with his doctor about things if he wanted an adjustment with his medication. He's open to trying things and wants to get better.

He's spent two nights at my place since this and while things aren't normal, they're not "bad" but they're definitely off (I think on both ends). I've brought the conversation up with him again and have reassured him about where I'm at. I've told him that I do not want to break up, that I want to be here and fight for and with him. He said that he's not at 100% (able to give 100%) right now but I told him that was okay. Over the last year I've been there and he told me SO many times that this is how relationships go - sometimes one partner has 100% to give and the other doesn't and it can go back and forth. I also wrote him a letter so that he has written proof of where I'm at and can look at it when needed. He also told me that there have been lingering "doubts" (I put it in quotations because he said that's not the right word he wanted to use, but the only one he had at the time) because he's worried about us wanting different futures. I have wanted to leave the city we're living in and he doesn't know that that's going to be a possibility any time soon (something that I am truly okay with and have told him & recently reassured him of). But it still gets to him, I guess.

He's told me countless times over the last year that he would never just leave me, that he would take a million steps before just leaving, like couples therapy or talking to me or so many other things. Everything that he told me on Saturday completely contradicts what he's told me this last year.

What can I do? I know that as much as I desperately want to fix things and make him (and us) feel better, I can't. I know what works for my mental health and what I need for support but him and I are different. I don't know what would work for him during this because I haven't gone through it with him. I asked what he needs and he doesn't completely know right now. This is all brand new so it's hard to know, obviously. I just want to be here. I don't want to lose him. I'm terrified of losing him and feel like it might happen - like this gut feeling that he might already be halfway gone. If us breaking up is truly what's best for him then I'm not going to fight it, like I said. To me, this doesn't feel like what's best for him, it's like it's what the depression wants and what this huge, scary situation wants. But I need some kind of advice on what to do or how I can be supportive throughout this.

Please, please help