I don't know if this will match with how your brain works, but I absolutely love this article   by author Susan Dennard on what do do when you get stuck planning/drafting. I know, the title of the article is weird, and I still laugh at the term "magical cookie".

But it did manage to put a name to something I hadn't been able to put a name to. Namely, that the best way to unstick yourself when you're stuck in a rut during a draft is to identify what sparked you to write the story in the first place and follow the path that allows you to explore those things the most. Susan says it a bunch better in the article (with detailed action plans, too!), though.