Nnnghhh, I feel for you. There are scenes like River/Eleven's first time in his perspective that I've wanted to write forever, but I've thought about it so often I just have too many scenarii and options swimming around my head
Oh! You just reminded me of the Wedding Night fic I had all planned out, but then Moffat went and made 'First Night' and a lot of it was jossed and yeah... Never got round to it. Darn. (TOO MUCH FIC TO WRITE OMG.) 'Twas v. good, though.