Don't know if i'm the problem

https://preview.redd.it/5ep38gputu5e1.jpg?width=1920&format=pjpg&auto=webp&s=dc01beed5618b1123ad755d6df73156873abfa78

I disn't played the beta so this is my first time and i can't seem to win any games, i don't know if its me who is just really bad but some heroes really feel unfair like jeff, iron fist or black widow, every time one of them is in the opponent team i can't do anything, i like to play support but its ether jeff who just gobble me specificly and throw me out of the map, iron fist who focuse me to hell or black widow who one shot me every time i enter her field of view so maybe i just don't know how to play but i'm considering stopping playing because all thoses game where pure pain