Im (M,19) and i can't seem to "love myself" even hearing it sound like bullshit, since I was little I've had suicidal thoughts and would bang my head against the floor because I knew it would make me cry in pain. I have deplegic cerebal palsy but, because I'm in good health and have been told I'm "good looking" (i don't believe that for one second) you wouldn't think for a second I have a hidden disability. To make things worse, my father abandoned me at 4yrs old, came back when I was 14, but only came once every 2 weeks and most of the time he couldn't come. So I don't actually know him, just basic facts, like where he was born and his St kitts background...that's it. I have a sister but we don't class each other as siblings. My mum told me that she wanted to be an only child and when I was born she hated me. Would always hit me as a child, try blame things on Me when it wasn't. She crossed the line the day before Christmas (2021). My nan always treated me and my sister blatantly different even my mother could see it crystal clear. I wanted nothing to do with my nan and I believed she didn't need an explanation on why, but, my sister insisted that I "be a real man" and tell her to her face. A few more things were said about me that made me blow my lid which I don't do because I am awkward. 
I've attempted suicide my trying to overdose on my A.d.d medication which was the highest dose I could get at the time for my age? Idk much about prescriptions, anyway. I had a girlfriend I 2019 but I broke up with her because we wernt making each other any happier just worse. I regret it so much because I still love her. 
I'm going to train in the marines commando in the next month or so, but, I don't know if I'm mentally prepared for it, physically yes 100% I'm just scared I fuck it up because of me and no one else. I believe this will make me happy but if I fail the course, I've told myself that, that will be the end because im not going to keep putting in effort and working min wage jobs for the rest of my life I hate it. 

There's so so so much more on why I want to end my life but this is just the basics. I'm worried because of how I've convinced myself that I will kill myself if the marines don't go to plan. Its 100% going to happen.