I feel tired and I want to give up. I'm not even worth it, but why do you guys still stand by me?

I thought yesterday was going to be my last day. My mom kinda drove me over the edge because I sent a picture in text to my friends that was this:

And she was very ashamed of me and disgusted, asked me what's going on in my head. I felt My friends didn't think it was inappropriate at all. But her reaction just killed me on the inside. Nobody has that power over me, except for my mom. I was so close to stabbing myself with scissors while I was crying because my suicidal and depressing thoughts were going on overload (they were already kind of bad earlier, but yeah that was almost the finishing blow).
They still kind of did this morning, but I'm doing better now.
I know I need to stop keeping to myself, but I always feel like a burden if I decide to talk about it.
It s funny how I want everybody to be positive and alive while I can't even do that for myself. But then... They deserve it more than I do. I was blessed with having a relatively stable home and everything a kid needed, yet I wasted it all. Which means now, I need to push through everything and make it all up, to show I'm not a failure even though I am now.
I'm sorry for nearly dying on all of you.