I really get this.

In my case I worry about deserving such things or waiting for some catastrophe to befall me that will turn it all into a disaster. I don't feel worthy of good things to the point that I have self-sabotaged them or avoided them happening.

I myself had a similar situation with a new car to me. As I waited I anticipated too something ruining the experience. When I did get the car I spent a month worrying over doing something wrong and was unable to enjoy it. It was as though I had the expectation it was all a mistake and that it would be taken away from me.