What do you do to get rid of your stress/anger/frutstration?

I used to exercise to get out my bottled up aggression but I can't anymore because literally anything could trigger the disorder in my knee and cause me to lose mobility in it. So, recently I started doing needle felt work. It actually helps a lot especially since I accidentally stab my finger like a thousand times without noticing until I'm done so I end up so I pretty much am so focused I no longer think of anything else. I just finished making a bunny holding a heart to give to my neighbor who's in the hospital ^-^ Two of my fingers need to be bandaged though but this a better alternative then constantly wanting to slap the hell out of people.