My anxiety is interfering in my relationship and I don't know what to do

So I've been dating this guy who's honestly great- smart, hot, driven, kind & funny- the whole package. Only problem was that he has a hard time expressing how he feels with words and would show that he cares through his actions, whereas I just tend to say it. Classic mismatch in love languages. Thing is, I was abused growing up and it's really screwed up my mental health. The depression/GAD stuff is one thing but the icing on the cake is that it's caused a lot of relationship anxiety for me (yes I am in treatment for these things but the r.a. stuff isn't gonna just go away). All of my emotions in regards to relationships are amplified 10× and I'm constantly so worried about losing people (friends, partners) over the tiniest things- I've never really felt secure. Our miscommunication thing just added to it so I broke it off. Tried to keep it friendly though, said I still want him around, brought up a fwb thing and even fixed the problems on his old Tinder profile to help him get back out there. That night though I kept waking up every 2 hours and it felt like a train hit me. First thing I'd think of is how he wasn't gonna call me when he gets off work like he normally does and it hurt like hell. Felt like a nightmare I couldn't wake up from and I realized I can really see a future with this guy, more so than with anyone else. So I called him and tried to fix things and he said it seems like I'm confused right now (he's right) and we should just keep going about like normal until I can figure out where I want our relationship to be. I asked him where he wants it to be and he said he thought he knew until I threw him for a loop and he just wants to see where things go now. I really hate knowing that I hurt him. We're in a weird place right now... While we were together we'd talked about how if he went to a party at my mostly girls school he'd totally get hit on and how I'd take him to one (knowing I'd be the one to take him home no matter what). But like, now he's still talking about it and about how he needs a wingman and I offered. I just want him to be happy and honestly the thought of him taking another girl home doesn't bother me...? I'm not saying I want an open relationship. I'm not interested in anyone else and I'm only fine with him having sex with another girl as long as I know about it and he comes back to me at the end of the night. Honestly my relationship anxiety has subsided a lot now that we're in the middle of things, I guess it feels more secure to have him around without a label because there's nothing to break off. I'm honestly terrified that with all my crazy roller coaster emotions I might just not capable of having a relationship. If we go back to straight-up dating all the nasty thoughts and worries are gonna come creeping back and start telling me that I want out again. I don't want to risk losing him to my own demons. I know we can't stay like this forever though, I have to figure out where I want things to go and it's all just a crazy jumbled mess right now. I have no idea what I want in a relationship. I just want him, I want his heart. I have no idea how to get there