how can I do this alone?

I have been crying in the shower.

I turn the water on hot and lay down in the tub. I sob, fetal position. Or I sit up with my arms wrapped around my legs and I rest my head on my knees. Sometimes I lay on my back and let the water massage my torso. But crying; always crying. Or that thing between sobs, when you can't catch your breath. It's like hiccuping backwards.
I keep waiting for the pressure in my breastbone to abate. It doesn't. It feels like there's a latch that needs to be lifted but I can't find it. I am so fucking sad and I have no idea what to do about it. When I am breaking down in the shower, I start making my suicide plans. I think "it is possible to drown in an inch of water." I wonder if I could keep my head there. I wonder if I could let my lungs fill. I wonder if I'd find some desire to live, if I attempted suicide again. I wonder if that's an addiction people have. Consecutive attempted suicides as a rush; as a way to feel alive. Try to die so you want to live.
I don't do it, though. I don't do it because I wouldn't want my roommate to find me. I don't want to hurt her. That is what's keeping me from dying right now. The thought of the pain it would cause my roommate. I don't worry about my family or my friends. I think about my roommate.
I think about jumping off the Point Street bridge. I consider the logistics. I wonder what pills I have that I could use to overdose. I wouldn't want to do THAT unless it killed me. I tried that avenue before and it was unpleasant to shit out charcoal for a week.
I can't slit my wrists. I wouldn't be strong enough. I hate the sight of blood. And I know I wouldn't cut deep enough.
Don't want to hang myself. Then someone would have to cut me down. And where would I do it anyway? Not the apartment. Maybe an abandoned building? It would be a while before anyone found me. I would be ok with that.
There are household items that are poisonous. That would be ok. I have thought about throwing myself off overpasses, but I wouldn't want to take people with me when I die. In my utter selfishness, I can still consider others. Does that mean there is hope for me?

I'm not going to kill myself. I'm getting to the point where every day that I survive is a small victory for me. I need that, because right now I feel like a failure in my own life. I feel like everything I do could be done in a better way. I feel stupid, and slow; like I'm missing something that everyone else can see. I am lonely. I am frightened. I feel used.
That's why I was crying tonight. I have been letting people use me. I let them use my body so I can feel close to someone for a while. I enjoy it too, but in the end they don't want me. They want my body.
I can't differentiate between the two so easily. A person is inseparable from their body. Right?

What is it about me that drives people away?