Stress is tricky because — as far as I can tell — it affects people very differently. In my case, I can cool off my stress very easily, but what happens is that I often take too long to realize the stress is piling up. I’m usually trying to focus on work, and then it dawns on me that I’m stressed up to my eyeballs, and the tension had been accumulating for a while.
Anyway, because stress affects people in different ways, what works for me may not work for you. But when I’m trying to relax, I usually play games, go on walks, listen to music, things like that. Writing helps a lot; I also enjoy cooking. You should try different things until you figure out what works, so try compiling a list of ideas from places like SuperMedical so you can try different items on that list the next time you’re stressed.