FPS ISSUE

Alright so i got a fps issue just randomly a few days after 8.9 update. Really cant understand why, so im asking anyone if u have a simple conclusion or if this has happend to some of u guys aswell?

I can admit tho that i have a shit PC although i cant see why that would be the problem when it has worked fine before and it still work on the level it should on other games?

Hard one to answer but thanks for anyone who will try to help.

Have a great day!