The makings of a Depressed mind

I feel extremely down.  I just don't know what to do anymore with my life. I'm 30 and just moved back at home.  Home is where all the demons that were once in hiding have come out and now  reveal themselves.  I've been running away from this place for over 7 years, and the fact that I'm back to square one just slowly kills me.  I'm reminded of all my failures.  I'm reminded of all the bullying.  The geographic cure was only temporary.  Before I moved home I was living on top of a mountain in a secluded community in Colorado at a retreat center that was quite cult like. I ended up in a psych ward for a 72 hour hold for suicidal ideation. I wanted to stab myself in the carotid artery with a broken Pelligrino glass bottle.  I wanted to use the top portion of the broken bottle and then rest it on the ground and put my body weight on it stabbing my sternum as well.  My plan was to do this high up in the mountains away from everybody, hoping that nobody would find me.  I wanted my body to decompose into the earth.
A month prior to this suicide ideation, I had another one. I was heading home for vacation and that morning I was planning on going home to take my father's blood pressure pills and drink bleach with it.  I have fairly low blood pressure to begin with, normally it's 90/50. I just wanted to make sure that I would die and there wouldn't be any chance of survival.  These plans never made it into action. Turns out after the psych ward in Colorado- I ended up moving home in early January.  By mid January, I was back in the emergency room for major depression and again, not wanting to live.  I was then placed in a psych ward yet again, This time I was held for 12 days. I got out about 1.5 weeks ago. I don't feel much different- still fantasizing that I die.  I try to bargain with God on a daily basis.  I beg him to take my soul instead of someone else's. I wish he would let those who fight to live live and those who fight to die, die. I don't get why a bargain can't be made. Even with the devil it can't be made.  I'm told that I haven't lived my purpose yet, but what is my purpose?   I just feel as though my purpose is to allow others to live off of me and my disease- drs. psychiatrist, psychologists, pharmaceutical companies. I have no more to give, I am broken, destroyed.  Who wants to be with someone like me? I don't even want to be me anymore.