What am I going to do?

The trick is to write. I know, I know that sounds stupid but the thing is that when the mind is crawling with images and situations and you can't focus on the proper topic, then we need help focusing. That help comes in the form of writing! Yes you will probably write too much on areas that are not needed in your thesis but, you can always delete! Plus those topics that you write about that don't belong are now on paper, they are out there not just swimming around in your head. The fact that you write them down helps the unnecessary disabling desire to constantly re-hash them in your mind! WRITE! Don't sit there looking at a blank paper, put something down. Even if it's the problems swimming in your head! Oddly enough I find those problems are being mulled over because they have a significant impact on the paper you are writing. Adds a personal touch to your thesis that the teachers enjoy. Good luck!