Where can I buy new p-oled screen?

Jakub Szendzielorz , It does not seem the LG has made the replacement screen available to the public only authorized service center's for LG can get them at the moment. Eventually they probably will come to market, I guess just keep checking Ebay, Amazon,etc for now or possibly pop into a local authorized service center's for LG and see if they would be willing to order you the part. Find below a disassembly link that may help if you do get a replacement screen. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.

LG G Watch R Teardown