Backround: I'm 15 (m), always struggled with depression + defensiveness + anger issues.

Recently one of my friends attempted suicide, and another is suicidal right now. My brother was suicidal less than a month ago.

It feels like im about to loose everyone i love and care about. And its been hard for me to cope with. Ive noticed myself having a lot more self harm and suicidal thoughts lately because of all this. I dont blame anyone, but its difficult for me to not just think that once they get better ill be fine, when im not fine. 

Im starting therapy but I feel like i dont have enough time to prevent anything. That within enough time my mind would take over and end it all. I dont want to be here, and I know that if i dont do something right in the near future I wont help myself enough. Im not actively trying to harm myself yet, but ive been thinking about it more and more and I feel like within then next weeks it will get there. 

It's hard to validate my feelings when everyone around seems to have it worse, I have no reason to be suicidal, but i am. 

My friend suggested a mental hospital, would that work? My parents have thought about it before, and i think they're open to the thought. But i just so clueless right now. I havent sleept week in weeks, and I dont think im thinking clearly anymore.