Should I be scared that he’ll do something crazy when I leave?

I was planning on leaving my current “situation”. He’s verbally abusive, manipulative, lies, threw something at me once. It’s just becoming way too draining. I can’t do it anymore. But I have been scared to leave him because he has things I told him that could sabotage my friendships (like venting to him when I was frustrated and still trusted him) and he’s already done it before, so I can’t imagine if I leave and he’s pissed about it, which he would be.

Earlier, I ran into a girl who a mutual friend (but isn’t his friend anymore) pointed out to be his ex. I asked her what he was like when they were together. She said they just slept together a few times and hung out, and then when she went to break it off, he told her that he was in love with her and wanted to get an apartment. But the mutual friend says that’s not true, that really they were together but then she started liking someone else instead and left him.

But the last time I heard from an ex of an abuser, at least some of it was accurate. It also for some reasons feels truthful to me. This scares me because it confirms my fear that he’ll do something crazy if I break off from him. The only thing that works in my favor is that I don’t think he’s as obsessive with me as he was this girl and I don’t think he’ll chase me if I leave. He doesn’t want to be together. We’ve also taken breaks before (on his terms tho) and he avoided me.