why cant I just fade into nothing?

My whole life has seemed a blur, like nothing is real and everything is just underlined with pain. I actually come from a successful and wealthy background, I have never been left wanting for more. However, for some reason the only thoughts  I seem to house are ones of suicide. It happens in the shower, at work, in bed, at family gatherings….. absolutely everywhere. Its like being tortured and destroyed from the inside out. About a year ago I met someone who was the first person I ever opened up to. I told him how I felt over time, and he promised to help and love me. I always had a nagging feeling in the back of mind that he would never stick it out. I blamed the  depression…. tried to brush it off as paranoia. We tried medication, therapy… anything we could think of to fix me…. but nothing worked. Recently, over the past few months, this boy has become more and more distant until one day he changed his facebook relationship status to single without a word. He never spoke to me about what was wrong, nor did he attempt to work together to overcome his feelings. The most he says to me is I ruined his happiness and he will take me back when he is ready, if he decides to. Every since this ive cried myself to sleep every night wondering how I am able to destroy other people when there is nothing of me left. I have no friends and no one I trust enough to speak to. My only friend is my puppy, he is the only thing stopping me from od-ing. I cry myself to sleep every night and wish I could fade away. I wish I knew how to make this pain end.