How to live life? I destroyed my life and now currently in the bottom?

I am a male college 3rd year student, from the Philippines. I am probably the loneliest in my cl everyday. I go to school then go directly home after school. I have not much friends, since I kinda destroyed my relationship with people because of my inability to be sociable like my other clmates. I also had no relationships with girls yet, since I tend to be scared to be with women. My life is full of woes, since childhood to my college years. I had lots of experiences that I don't even want to remember. I had once let a girl touch my thing when I was at grade 2, This was a painful experience I had when I was a kid. I became a laughing stock of the whole school because of it. I joined my batch basketball team on intramurals on grade 4, and made a fool of myself by trying to score on the opposite side, the one I should be defending. The whole school laughed at me for it. On the following years, I was always put down by lots of people. In 1 of my years in high school, my parents almost divorced. On my 3rd year in high school my father pointed a 45 cal pistol at me and fortunately he didn't fire at me but instead upward, all because I complained about him being always putting me down. I made my relationship with my relatives on my mother side worse because of being always negative with my life and not acting like what relatives should be. I failed on a prominent university by not attending my cles because of being negative and being very unsocial. And now i'm here back in my hometown, studying in a bad university, feeling bad with my life, having the same problems and still very unhappy. I tried a lot to change myself, but its hard, and I'm too afraid of the outcome, since I don't want to be made fun of again, being the laughing stock of the place. I tried to be easy going when I was a very serious person when I was a kid. People criticize me for being easygoing and called me mentally retarded. Then I tried to be serious, people called me a nerd for that. I had friends in high school. But it never lasts, they're all fakes in the end, I end up lonely in a corner weeping for myself for being so depressed, while people never know I was that depressed. The point is I have never ever known what I should do with my life. I always end up thinking negative all the time thinking I am never good for that, or that. I wish that I could be a much better and positive minded person. I want to achieve big, the one that God promised to give us. But I don't know how. Please help me and give me tips on making my life better. That is my only request. Thank you.