Stay or leave?

My bf and I have been together for 3 years and I need advice/opinions on whether I should stay and keep trying or leave. Our first year together was amazing. Total honeymoon phase and we were inseparable. The last year an a half we've been having problems. He has bad anger issues and we both have jealousy problems. He doesn't treat me how he used to and when he gets mad and we argue he calls me stupid and dummy and treats me like shit. And he's a hypocrite over certain things. He's allowed to do them but when I do it's a problem. He can't talk to me about anything without getting all mad. I've brought this up multiple times and said I didn't know if I could do it and he said he would change and never did. Recently we got into an argument and I told him I was tired of the shit and was done. Now he's swearing he will change and doesn't want to lose me and says he is sorry for everything he has put me through. It does seem like he's trying to change but it's only been 4 days so I don't know if it'll stay this way or go right back to normal after everything is settled down. And there is this guy at work who likes me and I sort of like him too. But I don't want to throw 3 years down the drain if there's a chance of saving my relationship. He thinks I should leave but of course he's going to say that. And now I fear hurting them both. So I'm stuck on whether to risk my bf not changing and try to work it out, or leave and start new and give someone else a try. PLEASE HELP! OPINIONS AND ADVICE WOULD BE GREAT!

If you're not in love with your BF anymore for whatever reasons and he's not giving you any opportunity to fall in love with him again, then you need to walk away. His anger and jealousy issues are his to sort. If you give him no reason to verbally abuse you and he thinks it's par for the course to do so, then you both need to realize that no relationship can survive with constant conflict, regardless of how much the people in it want to change. Your BF needs to change to keep you but only you know if he's capable of changing and taking the steps to address his bad anger issues. He needs to ID the reasons why he's angry and why he directs it towards you...the woman he's pushed away but doesn't want to lose. You also need to realize that you're not going to succeed at another relationship unless you end the one with your BF properly and get over him properly without looking back over your shoulder. You need to be tough enough on yourself to keep other people safe when your trying to work through your relationship issues. The guy at work is an example of this because you fear hurting him. You trust him enough to confide in him but he's thinking ahead to an unhealthy situation where there will be no winners. Your heart is getting in the way of your instinct and you need to listen to what your gut is telling you. When it comes to relationships, if your head, heart and gut line up, then you know all's well...when they don't, listen to your gut.

Thank you so much for taking the time to reply. I really appreciate it. And it helped me a lot to decide on what I need to do. Again thank you!