Disabled Husband asked for 6 month separation and I don't know what to do

This is a throw away for my privacy. I can contact mods on my main account if needed, but I don't want my husband following my paper trail, basically.

Tl;dr : Partner of roughly 21 years with depression, DID, migraines and Autism started asking for a divorce after meeting a new friend and put all his energy into spending time with her after spending a long time putting no energy into us. I freaked out and panicked and pushed him away by getting upset. He Asked me for a divorce but now we are in a separation trying to figure things out, but I'm trying to figure out how to save my marriage.

I've [33F] been with my husband [36M] for 21 years. We met online when I was 12 and I am almost 34. It was the romance story you hear of. He wrote me letters, argued with my dad until he got to come visit me, went to school near me so we could be together, and then we were happy for a long time... We broke up for one year at the end of 2017 because he cheated on me and left me to move in with the other woman. Then in late 2018 he came back to me with an engament ring and promise of a house ( we toured the house he ended up buying TOGETHER because he wanted me to pick the house ) We got married during COVID April 2021.

My husband has been in and out of work since I believe 2016. Eventually in 2020 he went on long term disability and has recently gotten SSD benefits. He has treatment resistant depression, DID, chronic migraines and Autism. He has tried every combo of drugs, done TMS multiple times, ECT, has had surgery to have a nerve stimulator put in... All to try and help with his depression. I do all the cooking, cleaning, yard work, driving. On occasion ive picked up a side job to help with expenses, but I'd get to a point where I'm too overwhelmed and about a year in I always end up quitting for my OWN mental health.

He only found out he has autism within the last year and since then everything is about how his Autism and Depression are never going to go away, make his life too hard to live and also makes it so he cannot be around me.

Apparently I am too stressful. I used to be the only person he could stand but now it seems like he just tollerates me. I don't know what I did wrong besides shutting down emotionally because it was just so hard for me. I told him I couldn't listen to him tell me every 30 minutes he wants to die. Everything we did together felt like I was dragging him along and trying to make him spend time with me. He stopped engaging in our kink and it felt like over all he told me "don't expect anything from me until I'm better." Which he also believes will never happen. So he shut down and stopped talking to me, too, which I don't blame him for.

This all boiled over when he found a friend. He has a lot of trouble making his own, and really has never had a "friend" that just wanted to be HIS friend and not OUR friend. She is nice, and has a boyfriend and my husband suggested we could be "couple friends." The issue is, he started spending ALL his time with her after telling me he has no energy and to expect nothing of him. He doesn't want to play games together unless she is playing. I begged him not to play Valorant with her because he wouldn't play Fortnite with me and I was terrified he was going to bond with another female and want to leave me again. I panicked. Her boyfriend started acting weird, so it never ended up becoming a "couples" friend group like my husband told me initially he wanted. It turned into him constantly being in calls with her and spending late nights talking with her instead of coming to bed with me.

I'm not so insecure to let him have a female friend, but all the patterns are there. This is almost exactly like when he cheated on me before. He feels like he can talk to this girl, connect with her and she "gives him energy" but at the same time he was adamant I am irreplaceable and can't be taken out of his life so easily.

3 weeks later he tells me we should get a divorce because he can't give me what I want and he is going to ruin my life. He can't do what I want and we should just end it.

I left the house almost immediately because I was so upset and felt like if I'm already stresseful to be around I should leave if I have any chance of saving things. I also thought it would be maybe a night or two at my brother's house before he would ask me to come home.

Nope. He wants a six month separation to figure things out, and it has been about a month at this point. I don't know what to do. I don't want to call a lawyer because it makes it feel like this is all too real. I don't want to get a divorce. I've put everything I have into loving him and I do LOVE him. It is like dumb fairytale unconditional love that I don't want to let go of, and I just think he is too depressed to see because my husband did this before. He tries to cut me out because of stress, clings to someone else, and then realizes he wants to be together. He is my best friend and I don't want to live without him. I just want to be there for him.

He still is talking with this new friend and things have gotten bad enough that her boyfriend has banned my husband from meeting her. He picked up interests that he hasn't had before and is driving long distances ( even tho this is not safe with his migraines and I've driven him everywhere for years..) to get food he has never tried because he is bonding with her... He didn't even have a Facebook until recently until he wanted to be on it to talk to her.

We are both in therapy, with the same therapist, who does also see us for couple sessions as well - she said we have to agree to be completely honest and open between our sessions to be as ethical as possible. He is being advised by both our therapist and myself to see a therapist who specializes in autism because our current therapist is doing her best but doesn't seem to be making a lot of progress.

Sorry this is long, it is somewhat a stream of consciousness in a moment where I am feeling lost and like I have no one I can talk to honestly. I don't want to leave him. I want it to work so bad but all my family and friends say to give up on this but I think we just need to restrengthen our communication and work on connecting while he also goes to therapy to understand his autism better.

Thanks for reading and for any advice in advance.