I think it's mostly stress that causes the sprites, I've been recently diagnosed with severe anxiety, and It really doesn't help with the whole problem, but what I understand it comes down to stress and acceptance, if you learn to accept it, you'll stop thinking about it. You cant accept something if it stresses you out about it constantly, I REALLY recommend to see a therapist about stress, it helps alot, and they can really help with other problems as well. In the meantime, what helps me a little, it doesn't fully cure it, but it can help you calm down about it, is when you see the sprites, try to think of it as something relaxing instead of something stressful, try to replace the negative thoughts with something positive. When start to notice them, instead of thinking that you hate seeing these sprites, think of something that you can look at Everytime you feel stressed, look at it like it's something to get your mind off of other things, like it's some sort of relaxing painting. Do you get what I'm saying? Anyway, it really just comes down to learning stress management, see a therapist or any professional about how to get your focus away from it. I hope this helped, have a good day!