Boyfriend with bipolar insists I’ve cheated on him

Someone saw my post in another group and suggested I join this group, so I’m posting here as well:

I’ve (38 F) known my boyfriend (36 M) for over three years now but we have only been officially together for about a year (anniversary is June 1st). I knew he had anxiety and thought he just had very bad mood swings but around the start of 2023, things got really bad and he lost his job and his lease wasn’t renewed (long story but he lived with the landlord and they didn’t get along). He was a recluse, wouldn’t leave his bedroom, would sleep all day, wouldn’t answer the phone. During this time he revealed he’s had Bipolar since he was 19. I could already tell at this point that he did.

Things seemed to get better when he moved back home but his mom had him mental health arrested in the Fall. I brought him back here to stay in order to give his mom a break. Things seemed to be going well and we decided to move in together. Things were tight financially as he was not working and I also have a ten year old on with Autism. I was under a lot of stress from work (I am a teacher) and my son had difficulty transitioning to a new team and building. Things got so bad at school that he ended up throwing a Chromebook at another student, hitting her in the head. That’s about the time when I stopped taking care of myself.

During this time, my bf took me not wanting to go out, sleeping, not cooking as much, being less talkative as a “sign” that there must be someone else. This has been going on and continues to this day.

He’s always had access to my phone because I have nothing to hide. But I found that he would spend nights scrolling through social media, bothered by posts I “loved” if the person was a male, insisted conversations where I checked in on someone who had been sick, were all signs of infidelity. If a stain popped up in the car then he’d insist it was semen. It got to the point where I think he was doing things to try to catch me in a lie. He found frosting on the fridge from his birthday cake and insisted I must have f***** someone while he was visiting family back home for a few days.

We have both been cheated on in previous relationships. I know it took me years to heal from my son’s biological father’s infidelity, and I understand his fears but the constant accusations took a toll. Fights got more aggressive. Glass has been thrown, and things have been thrown or knocked over. During one of the fights, I was in the bathroom and he managed to break the lock and take molding off to get in. Fights continued and for everyone’s safety, he needed to go back and stay with his mom. He is still there but swears I’ve cheated on him and discarded him.

I love him and can’t imagine my life without him. I have purchased semen test kits to prove car stains were beverages. I got hypnotized to verify that no one has been inside of our home. I don’t know what to do. He keeps saying I need to take accountability and he has proof but shows me nothing. And this is where I feel completely gaslit because I haven’t done anything that would even be in a gray area. I have literally struggled to perform basic functions these past few months and he tells me I kept discarding him. He also tells me I’m projecting and sends videos to me about narcissism.

I want him to seek out treatment but he swears he is okay and this has nothing to do with his bipolar. To me, he shows signs of Border Personality Disorder but shrugs me off and tells me he doesn’t have bipolar and was misdiagnosed.

Is there anything I can do to help him get treatment? Is this a relationship I should fight for? I don’t know how to navigate this and didn’t realize the severity of his mental health until we started living together and I don’t know how to work through this right now.

Advice would be appreciated but please try to be kind as I’m doing the best I can at the moment.