Should I try to fix this relationship or put it to an end?

My boyfriend and I have been together for four months. In that four months, he's gotten fired from his job, drank nearly every night, and ditched me numerous times for his friends/to party, etc. Now I understand that he's 20 years old and wants to have fun, but he's proven his immaturity, irresponsibility, and carelessness to me. Should I end it, or talk to him? He's a great guy, so kind and sweet, he makes me laugh. But he isn't good at being there for me when bad things happen, although I'm only 18 and a freshman in college, I can't stand the thought of being with someone who has no intentions of going anywhere with his future. Help!