What should I do about my relationship issues?

Well, to be honest I'm having a few relationship problems. A couple months ago my girlfriend of almost 5 years broke up with me. She broke up with me because I've had problems with not paying attention to her more than I should for the past two years. And I've just been an *** too with the terrible job I had I took it out on her sometimes when I would get home from work. But when she left she found someone else that she really thought was a cool person...but all along I've always known there is just something wrong with that guy. After being with him for a couple weeks she can't stand the guy because he's even worse than I ever was! But he's one of those guys that's always mad about nothing and treats her like crap. So now my ex is trying to break up with him to be with me but he makes her feel guilty and stuff so she hasn't broken up with him yet. She doesn't wanna get back with me right away or nothing but she wants to be single for a bit at least which is cool. But she doesn't really have the heart to tell him to leave her alone. She's a very soft-hearted person too so I'm worried that he will some how muscle her to stay with him. And he's hated me from the start just because he's an angry person who hates everyone and everything unless it has a vagina! But he really hates me now that me and my ex have bumped uglies so to say while she doesn't even want to be with that dill-hole. I just don't know what to tell her or how to tell her she needs to not want to be around him at all...because he's a pretty much a pathological liar too. There is soooo much stuff he says that you know just from hearing what he says you know he's lying. Please....help lol