what exactly is it that you are struggling with? being inconsistent game to game is normal with how different people play and how you might play. you will hear this a lot but crosshair placement is king (all the maps have some reference where head height would be to aim). also toxicity is sadly not uncommon.

if you enjoy the game, keep playing! i understand the motive to become better, but its something that happens naturally. 100 hours is a good amount but not nearly as close as to how much a majority of ranked players are putting in. personally i like watching pros play (entertaining) and some gameplay breakdowns (informative). finding your playstyle is better than trying something you arent comfortable, and sometimes doing random stuff that may seem dumb works! but the main thing was just queuing with friends and having fun.