My life has no meaning, purpose or substance?

I have been in a world of hurt for quite a long time. Being 18 and leaving high school. I had this mind set. That I would get out there and start my life. That college would make a difference. I am going to college in 2 months. But my social and family life has never been perfect. I have to to this epiphany that I never had real friends. I think the people I have always hung out with are just friends because they are there. I don't feel the bond, that feeling that true friends should have. My family is terrible. My parents are constant work-aholics who are always on my case, thinking that I can never think for myself. My sister is 13 and all she does is swear and acts like a total disrespectful person. My brother is socially inept and always boring to be around. My quest for love has been a complete failure. I had 2 girlfriends in the past and that was a bomb. The reason why I posted this under LGBT is because 1/3 of my crisis is "sexual confusion". for 6 years I have questioned my sexuality. All throughout my life its been dominantly females. But when I turned 18, the tide shifted to men(sexually) The closest I ever get to homosexuality is gay porn and I recently dated this 21 year old who I am actually attracted to(personality wise too) I dated him for a couple das but broke up because I am afraid of homosexual dating in public. He told me he was aware and not to be angry, he understood and we are still great friends. But I am also under this impression that love doesn't exist and I have no future. There are times where I want to throw myself in front of a bus or just jump off the empire state building. I just feel things are changing for the worst and nothing will ever get better. I am acting like the way I didn't when I was really young. i am going back to an infantile stage of behavior and have a bad outlook on everything. Like what woman or man would ever want to be with me? or anyone be my friend for that matter