I have no idea where to go with my life..?

I am a senior in high school and my life sucks. I have been diagnosed with clinical depression and was put on antidepressants a little while back, but I did not like them so I went off them. I had a girlfriend a little while back that I have found it very hard to get over. Its been almost 5 and a half months and I still think about her. I want to forget about her and get on with my life but I just cant seem to get over it. I hate the highschool I goto, and I hate the people I hang out with at times. My grades were good freshman year but they have steadily declined ever since then. I also smoke and drink, but I do not think that this has ever contributed to my problems, because I feel it is my parents who tend to make me feel the worst at times. They try to lock me in a prison at my house. My mom and dad never stop fighting, and they call me 5 to 6 times to see where I am when I go out. I wish they would just lay off. My mom always thinks im out drinking and smoking, and she has asked me every time in the past couple of months whenever I come home late from something or go out on a saturday night. It honestly makes me want to punch her in the face. I feel like everybody has a better life then me, and I tend to be jealous of those that do. It seems like nothing goes right with my life. I also think I have an anxiety problem, and due to this keeps me from communicating with other people, it pisses me off so much on the inside. Ever since I was born I have never enjoyed anything about my life. Where can I turn? Because I will probably just kill myself if I cant change anything about it.