I really need some solid advice right now

I having a mental breakdown and really need some input as to how to move forward. Long story short been together now 3 decades, no kids but we have 5 pets. Surface level we are fine but have underlying major issues. He can treat me so kindly and is a good man but he can also be mean at times. We have had a rocky road over the years.A few years ago we started acting more like roommates. I thought maybe this was normal for a relationship that was 3 decades in. No passion but a true friendship and I loved him and I thought he loved me. I found out 2 years ago he was having an affair with an old friend. No sex but it was going there but I found out before it happened. I asked him if he wanted to try to make it work with us and he said yes. I wanted to make it work too. I no longer trusted him and I was looking for proof. Then 5 months ago I found out she reached out to him and they started hanging out again. I was able to read some texts in which he told her that he hopes she would find some one new and he didn't want to hurt her but he didn't want to hurt me either and he didn't know how to navigate with me in how they could continue to be friends.There were also a lot of of texts he has deleted before I could read them and I have no idea what those said. Again, I gave him another chance to prove himself but was still looking to find evidence that something may still be going on. Nothing found. Now he also has another female coworker where they have to travel a lot together and over the last few years I have known that they text each other a lot. Some work related but a lot of the texts are about our pets, what he did at the gym, her suggesting ideas of what to name our new cat. Stuff that made me uncomfortable with. Nothing sexual but seemed to be a little flirty trying to impress. When I asked him to cool it with her he told me they're just friends and I'm overreacting. I'm sure nothing sexual happened but it seemed like a door was opening. Last week he got home from a trip and I found a text where he was going to buy her a T-shirt at the airport but it cost too much so he didn't. She responded with. . " I would be so mad if you bought me that shirt" hahaha"his response was damn if I wasn't boarding the plane I would go back and get it. I lost it became unhinged and texted her not to ever text him again and that she should just text her boyfriend. Him and I got into an argument and then I apologized for texting her. It was wrong of me and I deeply regret it. I asked him to tell her that I was so sorry and that I wasn't angry with her but my issue was with him. They are now working together in another country at this time and he has texted me that she refuses to speak with him and has made it impossible to work with (they work hand in hand)she is acting like a crazy person and that he will lose his job because of me. He is pissed and I know that I have caused a major issue for him. He proceeded to tell me he doesn't love me and he doesn't care if I move out or not. I may be in denial but part of me thinks what he is telling me is true and the other part thinks he is saying it out of anger. If I move out, it was a major hardship on me, I will have to move out of the city so I will lose my job. I cannot make it on my own currently. If afraid when he gets home because I know this will go nuclear. Not that he will hurt me physically but he may threaten to throw my stuff out or cut me to the core. Since his job is on the line, this is a big deal. I don't know if I should stay and let things cool down like they have in the past or pack my stuff and be gone before he gets back in two weeks. I feel so ashamed of what I have done. I don't think this can be repaired and yet I'm afraid of losing him I hope that somehow we can rebuild a better life. What would you do if you walked in my shoes?