Boyfriend says things he supposedly doesn’t mean when upset

So my (25f) boyfriend (24m) of six years has an issue with saying things he “doesn’t mean” when he’s annoyed or angry. One time he quietly said “fuck you” to me then proceeded to leave my apartment. Another time he broke up with me and once he got home from work and had more time to think (his words) he took it back and asked if I still wanted to be with him. There was another instance where he said he felt trapped in the relationship because he didn’t want to break up with me for fear that I’d commit suicide because I was suicidal. He took that back as well and said he didn’t mean it.

I’ve told him I think he means these things and just keeps them bottled up but let’s them out when he’s angry. He promised it’s not the case, that he just says things when he’s mad.

Today was something small but nonetheless annoyed me. He misheard me on the phone, he thought I didn’t want to pass by a store before he dropped me off at my college. While in the car I asked if we were going to the store. He said no, the ton the phone I said I didn’t want to go. I told him I never said that, and that I said the complete opposite. He asked what I said and I told him I couldn’t remember word per word but that I knew I had said I wanted to go. He kept saying that i did not say unwanted to go and pointed out that I I can’t even remember what I said.

We argued and later at night when we cooled down, I told him I didn’t appreciate him saying the whole “u can’t even remember what u said” thing. To which he said he was, “speaking out of his ass” and apologized.

I told him that this is the reason why I don’t like arguing with him, especially in the heat of the moment because this happens, he says things then takes them back. And I’ve always been scared of him saying something like “f-u” again even though that was years ago and never happened again. I still fear it happening. You just can’t take that back.

He will always want to “fix things” in the moment but when I tell him what’s wrong he will get annoyed and stay quiet. So I just stay quiet too. I don’t need him “speaking out his ass” if I try talking to him. We then will talk to each other again hours later. But I don’t like this. I can’t have us be stonewalling each other” but I also can’t have us arguing in the heat. Plus, sometimes he still ends up saying something he doesn’t mean even after taking so much time to chill out before talking again. Im at a loss for what to do.

It doesn’t help that I lived in an abusive home and cannot handle even raising our voices at each other. I don’t know if it’s “normal” to say things you don’t mean to your partner when angry. Or if raising your voice is normal, since I avoid these things and just go silent mode because everything reminds me of my dad’s abusive a$$.

Tl;dr

When my bf is mad he will say some things that he will alter take back once he’s cooled off. For this reason, I don’t like arguing with him in the heat of the moment. However, I also don’t like us cooling down for hours before coming back and discussing whatever for us upset. I don’t know what we could do