I can't play my game and I don't know how to fix it
So recently I received a notification on my computer when I tried opening app my Sims 4 game. It said something along the lines of "do you allow the application to make changes to your computer?" and I meant to press yes since I knew it was talking about the Sims, but I accidentally pressed no. Once I did that and tried to open up the game a notification keeps popping up saying "Unable to start: The Sims4 is already running." and following that notification would be a bunch of letters and numbers. I don't know how to fix this issue. I have tried uninstalling the game and origin and every time I do that and try to open up the game again it goes straight to that notification. How do I get rid of this notification and be able to play my game again? I don't want to lose all the expansion packs I have bought cause I spent hundreds of dollars on these expansion packs and I don't want this to remove them all.