New Discovery in Myself

I had a thought today, I have thoughts often but this one hit me really hard. I was getting ready to leave for school and I realized I am just tired. Not a sleepy tired either, like I am mentally exhausted. I stood there putting on my pants and just started to cry. I don't really know what has been wrong with me since I came home from school in May (really before that...my heart borke and my mom says that something else broke too.) I realized today that I don't know if I am tired of trying to make people believe that I am okay or if I am tired from trying to make myself believe I am okay. I'm not okay. I have not been okay for a while now. I don't see a future for myself, I don't want to do anything but look up people I don't know on tumblr and here and sleep. That is like my current life goal. I am so far from being okay that I don't even know what okay is anymore...I have not been "me" in so long. Sure I laugh and I get excited about stuff but I can't remember the last time I was happy for a prolonged period of time...I don't know what happy is really. I don't know what to do anymore. I never thought I would or could be a self harmer but those thoughts have been almost a constant in my head recently. I just want to feel something again. I don't know what this means for me and while I know it should scare me it doesn't...I gave myself a bruise last night on my hip from just hitting it and I felt good about it...I don't want to be this. I don't want to be the girl that sits and thinks about how I can hide the fact that I don't want to eat anymore and when I do I want to go throw up (just thoughts right now...too attached to food to stop and too afraid to make myself throw up...) Truth is I don't know how much longer I can do this.
I don't know how much longer I can go on only letting people get a glimps into what I am feeling...how far can I bend under this pressure until I break down and just give in to it?
Who am I?