Dueling dragons

My boyfriend is horrible. I mean abusive in many ways, an alcoholic, cheated in the past, lies, and more that I can't even share here. Lately I have felt he's been growing up, in very tiny strides, but his manipulative, selfish behavior is still there (as well as the blackout drinking). 
I feel stuck though. I've invested years with him and I'm already mentally hanging on by a string at this point in my life. Breaking up the relationship from the person I'm closest too might actually destroy me. I'm already depressed enough, ending a relationship is another death to endure and grieve. I'm grieving my own losses still. I don't think I could handle it. I know I couldn't.
The issue is, a male friend of mine wants to take me out. He's a great guy, stable, successful, but you never really know the real person until you're in a relationship with them right? I could be making him out to be this Prince Charming when really he's just another abusive asshat. Anyway, it takes a lot for me to like someone. Usually I'm disgusted by any guy who shows that kind of interest in me, but I feel differently about him. I feel like he may even be too good for me and I'm so damaged from my current relationship I'd just ruin him. 
What I really want to know is, is it okay to hang out with my friend? Specifically go get dinner somewhere. I know theres no way in hell I could tell my bf or he'd be okay with it, but if he is acting like I don't matter to him and neglecting me, not committed to me, am I doing anything wrong by hanging out with other people? Im not even sure he knows I have a boyfriend, most people don't realize it because he's so absent from my life. So I feel weird about that too. This is so unlike me. I haven't been with anyone else in years, even when we broke up for a few weeks here and there. Him on the other hand, has been with many other people since we started dating. I'm sure I don't even know the half of it. Anyway im sorry this is getting so long. I just feel very conflicted. I read somewhere years ago the key to being the type of woman a guy wants to commit to and respect, is to live your own life and until you have a real commitment from a man, you're free to do whatever you want, including seeing other men. I sort of agree, but I've never done that before. Is it wrong to start now? Also, I'd never break up with one person for someone else. So I won't dump my boyfriend for this other guy just because he's the only other guy I've been attracted to in years, because who knows what he's really like. Is it wrong or okay to go to dinner with my male friend? Thanks everyone