Looking to upgrade my pc not sure what do much help would be appreciated!

I currently have a budget pc that was around 500$ specs (ryzen 3, 8gb ram, Radeon RX570, 1tb sshd) I am mainly just trying to get rust to run smoothly I play at the minimum setting and still get major frame drops making the game almost unplayable. I have around 300$ saved up but do not know what I should upgrade and what to get. Any suggestions? Thanks!