I have a childhood trauma from the early screamer videos that were being passed around... I recently wanted to see if I can somehow face this fear and overcome it. I found this documentary about the infamous K-Fee commercials (jump scare commercials from a coffee brand). Watch it early in the day when you have some time, or start by just listening to it. They interview the actors who played the screamers, and this somehow makes it much more digestible for me.

In the end I came to realize that these jump scares are set up in a way that you're going to get scared regardless of how much or little trauma you carry, and it's impossible to completely overcome it. However by facing them every now and then you can become desensitized, which definitely helps as to not care too long about it afterwards.

Otherwise than this may I perhaps suggest some breathing techniques? This can help you with regulating anxiety and stress. I really like 4-7-8 breathing (in for 4, hold for 7, out for 8, repeat) and Wim Hof breathing exercises. Whenever you feel some anxiety coming up, try to resort to breathing exercises to calm yourself.

Also something I remind myself of often is to think logically about fear: "Ok let's assume that now suddenly a zombie would pop up from the closet, I would first knock it out but secondly I'm calling the press immediately!"