Game Closing out of nowhere and Inventory issues

Hi.
As the title says, my game has been closing out of nowhere but also got another wierd issue.

So, a friend of mine recently used his account on my pc, he has everything bought, packs, premium pass etc etc.
The thing is, when i use my account, his progress (including the in game ranks and speed pass progress) somehow got combined with my save.
and thanks to that i get a lot of errors regarding an "Inventory Issue" causing the game to not let me play online.

So, is there a way to remove all of my progress including that Rank and Speed Pass progress? i already tried deleting the save on the Documents folder but it didnt work.

Thanks in advance.