I hate it when things keep going on and on and on and on in my head. I'm sorry I have nothing productive to say particularly but I understand.
I get annoying when that happens because I just keep talking and talking and don't shut up because by talking the thoughts stop - not that good an idea if trying to sleep. I try reading until I am just about fallen asleep because once I stop, the thoughts start again. I also go for long runs to try and make myself so exhausted that I can't stay awake.

Hope you can get some sleep.