It sounds like anxiety. I have these same obsessive almost OCD thoughts. Sometimes it can be something simple like buying a shirt I saw. I get obsessive and can't stop thinking about it until I go do it, which resolves the anxiety. It can be what I'm going to order in a restaurant when it's days away. It can be more serious issues as well. I can't stop thinking about it no matter what. Over and over, imagining different scenarios and outcomes. To help I do research if applicable and other times I simply do not let myself think about it. When I start, I make myself stop and think of something else because once I start I won't stop. I heard once that with these obsessive thoughts it may help to go ahead and think of the worst possible outcomes. Sometimes this can show that you can get through it, thinking worst-case scenario situations and finding their solutions. I hope everything works out, but I just wanted to say I most definitely understand obsessive thinking.