What starts as drinking on weekends and getting wasted maybe once a week, turns into drinking 3-4 times a week, than maybe 4-5 times a week. When you start to feel alone and "need a drink", when you want to have fun, but you "need a drink", when you are under lots of stress and "you need a drink", those are signs that you are becoming an alcoholic.
Please seek help and talk about it. Alcoholism is dangerous and kills you, makes you an outsider and loner over time. Please don't feel ashamed. Seek help, talk to friends/family.