Hiya Kel,
I used to get that a lot. When I had vacation time coming I would get anxious because I would get scared that I would feel bad and ruin my vacation. and because I kept thinking that I would get to feeling bad on my days off and that would reiforce my beliefs and so on... But there is a way out of this. Exposure work, baby steps and thought challenging is really what got me out of this pattern. Anyway, sorry I can't be more helpful. Remember, you can change all this, it is in your power to feel better. This too shall pass!
-Diva