Why can't I stop feeling like this?

(I am just venting) I am on the edge. I have my whole life ahead of me. I've had a genuinely nice life. I have a loving mother, friends, and i even had a lovely SO. But I pushed them away. I shut everyone out. I struggle day to day with my mother. I can't even go hours without crying. The best part of my day is coming home to cry. I scream. I sob. I hate how fucking cruel my brain is. Why do i keep telling myself to die? That I'm worthless? I pushed away the only person I've ever opened up to and fucked up my relationship with them and hurt them. I need someone to talk to so bad, but I stay further and further away from everything. I can't open up to my friends either. I know my best friend has her fair deal of problems and don't want to hurt or dump my feelings on her. I can't help feeling the need to die. I feel like I am burden and a waste of space. I am so fucking tired of feeling helpless and like nothing ever gets better. It's better periodically. I just feel like I spiral worse and worse each time and each year, my depression gets worse. I've also recently just started to finally accept and stop denying that I am depressed. I am suicidal. I want to die. I feel like i deserve to. How will this ever stop? I feel like I'm stuck in a lifeless cycle of negativity even when i try to talk myself out of feeling sad. Or that my life has meaning. When i reflect on my actions and try to think of a way to fix my situation, I think of other things that can go wrong and backtrack all the positive thoughts. I want to turn to drugs sometimes or substance abuse because I feel like that will help numb the pain. Does it ever truly stop?