Should this even be here?

I seriously don't know what to do anymore, I have tried everything I can, but it does not help. I might be 20, but i can say that i was already dead inside when i was 15... i am sick and tired of keep setting high expectations for myself, because that was what i was taught when i was young. i am sick and tired of setting high  expectations for myself that deep inside, does not matter to me, and does not make me feel alive. I felt like my life was never mine, despite people keep telling me that they will support me for whatever i did, i never once felt like i was even supported. Even when i did finally achieve what i wanted and showed that i made results, they would often be gone unnoticed and criticized. They would often state that my results was not from my own hard work, but due to the reliance i had on others and due to the hard work of others to make me do well, even when i struggled so much emotionally and i tried to hide it from everyone because i never wanted to let anyone knew i was struggling and i was on the verge of trying to give up and end my life when i was about to do so. In the end, i stayed alive despite not knowing how to hold through because i knew that if i did something to end my life, there are people who would feel so sad and blame themselves for my downfall, which honestly was all my fault because i let those stuffs affect me, and trying to hit goals and expectations of what people wanted to see, instead of what i wanted for myself. Slowly, those goals became blurred and i slowly accepted the fact that following the social norms was the only way to go. I gave up my A Levels last year, and failed badly. I decided to repeat, not because I really wanted the to do well and get into a university and all, but because i wanted to prove to myself that i had the discipline to do stuffs that i really hate and dont want to do, but looking at it at this point of time, it is not really working out well. im scared, and im really extremely scared of what may follow next. Would i fail all over again, and be classified as a useless piece of trash that my parents no longer want to invest into? Would i look like an idiot that i repeated again and then failed? I am also afraid about what will happen if i put in the effort. If i put in the effort and fail again, would there be any use? If i do pass and score really well for A Levels, and get into a university, what happens then? If i cannot take the stress, pressure and amount of work required to do for A Lvls, how about university? I would end up struggling further. I feel so dead inside, and i am trying to find reasons to live and survive each day, but i cant. I dont know if i can take it anymore, even if i do manage to survive physically, i dont know what will happen. i am very afraid about who i will become and what kind of monster i will turn into anymore. I dont even know who am i, and what i really want of myself anymore. all my current goals and 'dream' to become a pro bowler, honestly, it is just a simple escape and method for me to run away from reality. Who am I, what is my identity and what represents me as a person? I dont really know anymore because i am so messed up inside. I am just a person who has been given a name, just trying to act everything is alright and that i have a certain goal and target to achieve, but whenever i am told to write a letter to myself, i dont know what to write, because i didnt knew and never knew who i really am inside since i was 15 or so.... i lost myself.