It depends where I am. I've found betabockers are great if I'm at work or somewhere I can't just remove myself from the situation.

If i'm at home I use one of two methods. The easy one is to go for a run, use the stress make you keep running. Once your legs are battered and you can barely breath, your body will naturally compensate with dopamine that helps you have a better look at the situation also whatever has been stressing you out feels like nothing compared to how bad you feel in that moment. The best thing about that is that the worse you are at running the quicker you get to that point and you can go home feeling refreshed.

The second way is a form of meditation I've used a few times to deal with suborn issues. I'll sit down for an hour, with my eyes closed and relaxing music playing then just focus on whatever is stressing me out. It can take a few times of doing this to really find a solution or accept the situation and it can be hard to force yourself to sit there and constantly think about something that your mind probably doesn't want to focus on but it really helps. Even if I don't particularly find the "answer" to whatever is bugging me, sitting down for so long with the relaxing music playing and thinking about it naturally starts your mind to associate that issue with being relaxed and safe at home.

Doing a mix of these three, I don't get stressed that often. Mixing the meditation with betablockers also helps.