Sorry you are struggling. Have you had a good night's sleep? Yes, I think switching to a different topic is a good thought. How much time have you spent on your current topic? If it is a topic you are interested in, maybe you will find yourself using what you've learned, but towards a different goal. Starting over when you are feeling defeated in not a bad idea. Don't psych yourself out. You can always start over again if you need to. Also, here is a link to PC's SI forum if you need more support.

https://psychcentralforums.com/self-injury/