I feel so shitty and I hate letting people down.

I work part time because I can't hold down a fulltime job. Even though I work part time, i STILL can't hold that down. I'll be fine for a few weeks and then all of a sudden I can't get up for work either because I genuinely can't or because I feel too shitty to get up and I curse the people at my job and the job itself because I don't wanna go. I just split on the entire thing sometimes and I just don't care, and as soon as I've told them I'm not going in I feel bad and have regret. 

I can't handle being under pressure to have 100% attendance. Every single job I've had, people get pissy when you mention mental health reasons on why you can't come in. I'm just tired of life and it's all just making me suicidal, want to self harm and/or use substance abuse as a way to stop thinking about it. I've had enough of constantly turning up to be treated like shit no matter what job I'm in. I could do 1 million nice things and 1 bad thing ( not turning up) and it's the end of the world. 

There is nothing I want to do, nothing that would get me out of bed each morning and I'm tired of people saying "get a job you love then" for that exact reason. I want to be able to get out of bed everyday and love my job and not give a shit about people. I just feel so stuck and I don't wanna / dont know if i can get allowance instead of working because people would just see me as a lazy slob. I am so done with every thing I hate myself so much and as im reading through this now, it doesn't even sound like much but it's fucking one of the many things largely wrong with me and I hate it, I would just like to die.