Where do I go for help with getting better?

I have been playing this game since season 0, and played one character for over 120 hours. I keep losing no matter how long I play, I have a 51 percent win rate with that character. It’s said good players get to the rank they deserve but I keep losing no matter how many hours I waste on this game. I just can’t take it anymore, is there a community of high ranked players where can I send my replays for review?