You need to grow a backbone. Your very dependent on him and its very unhealthy. You cry for hours if he doesn't call? That is not normal. Do you have friends in college? Hobbies? Family? Right now your acting like hes the only thing worth living for.. you need to get a life outside of him and start living it to the full. Your 24, you have youth on your side. Yiu have the whole world at your feet with so many options and great opportunities coming your way. Your about to graduate which is a time to celebrate all your hard work. You will gain much independence when you start working in your field, meet new people, make new friends..
Honestly this guy is abusing you. You cling to the occasional times hes nice only to feel like absolute shit when he isn't. Its a game and hes playing you. Hes only nice because he wants you to remember that each time he gives you a reason to dump him. Where is your self respect? Your self worth? Why are you settling for this?
The guy is in his 30's, has an alcohol problem, treats you badly, doesn't care about your feelings, is going nowhere with his life and if he hasn't grown up by now-he never will. He will never make a good husband or father. Stop wasting your time on this loser. Dump him, focus on your future and heal from the breakup. Meet a nice guy your own age who is on the same page as you in terms of future goals and who us as invested in you emotionally as you are.
I know right now you think you will be devastated if you break up but you are miserable with him. You will only feel like crap for a short time once you dump him and then you will gradually start to feel better. Look up the five stages of grief. You will get over him and it will lead you closer to a happier future
"Don't ask a question if you can't handle the answer".