i was eating parle g ( iydk jjust google) when i realised a soury itchyness in my tongue i ignored it and continiue eating it turns out there were red ants which attacked the parle g

I'm a former 1700 ELO. Simple tips are no longer that helpful for me. Rn the 1600s and 1700s are clearly stronger than the time I just reached this level. Even 75+ or 80+ accuracy or sometimes 90 accuracy can't really beat them. And my chess skills also aren't that well after not having ways to improve for months(due to previous exam) I need to find a way to ensure myself to have 85+ accuracy every single game. Or else it's basically unwinnable for me coz one single calculate mistake= lose in high elo chess. Any people with high ratings can leave few comments? Comparing with my bestie , we both stared at around 500 elo beginners years ago but he is now 1800 playing 85+ or 90 accuracy almost every games while I'm 1600 playing badly. I think our different is the way of calculating. Idk why is my calculations also having useful ideas but they are wrong( unobvious errors) or when I have the right ideas, I still make errors in moves. Damn chess is hard af