I’m sorry to hear that but that is just the reality of this game or any other online games etc. and its gotten worse every year,
This is the reason i never ever bothered playing comp in the first place, and yes qp has some toxicity but its tamer compared to comp.
I found arcade to be more engaging and fun specially custom games and its where i mostly spend when i want to have fun.
Id say drop the comp, it is not worth it
Youve already accomplished reaching rank 3000- 4000 as you say so there is not much to prove. Just play the game casually and you will find it still enjoyable.