Just do it.

If there's something you need to do, just do it. Now.

Chances are it's not going to take as long as you think. Nor will it be as painful as you fear. And even if it is, you'll be done with it at some point. And then it will be over.

Would you rather be done with something and forget about it or still be thinking about it and be dreading doing it?

The sooner you do the thing the sooner you can guiltlessly move onto something you do want to do.