Contemplating becoming a nihilist

the past 4 years have been traumatic, morbid and extremely hard to cope. I've gained a lot of knowledge on life from being in certain situations, being in Pyschwxrds, rehabs, recovery, 1 year camps (that I didnt complete) and I've applied it there and there in my life but you know what they say... Life goes up and down. Well fucker it keeps going down everytime I fail at doing something good for myself. I haven't had a job in 3 months cause I was dxpressed or maybe just laziness and today was my first day at work I was excited about it but no one communicated, they threw me in a pack of wolves another thing is that I'm absolute dog shit with technology and I had to take peoples orders and it was just all so overwhelming. So I left didn't talk to themanager or anything, I just left the cash register picked up my back pack and walked out the back and started screaming at the top of my lungs and had a mxntal breakdown cause I've been filled with so much self hatred for being anxioxs and failing again. I feel so defeated and the thing is that I'm 21 and I just want to fucking succeed in life and be free and be at peace and just feel FUCKING SANE!!! This is me coming into manhood or just growing up. I keep pushing myself to do better and do better and do better but I just fuck it up cause of what ? My anxity ? Deprssion ? MY STUPID FUCKING MENTAL HEALTH ? ITS FUCKING RETARDED THIS MENTAL HEALTH BULLSHIT!!! Please someone help me!!!