I have been stuck in bronze for forever, once was gold, don't know where that guy went...

I have tried everything, playing duelists, sentinels, initiators, etc.(reyna, sage, cypher, omen, breach), reached gold with reyna but now I play her its either very good or very bad.

I do crosshair placement, I stop while shooting, I aim for the head, I have low sens, I'm doing aim labs, what is wrong here?

I just panic when fighting and accidently press d or something. I'm about to give up.

Edit: also, random question, how important is polling rate? I notice most pros have 1000hz while I have 250hz(on wireless mouse).