Have OCD, diagnosed, take meds.
OCD is easily summed as "the doubting disease". It's made up of intrusive thoughts which are persistent... these thoughts cause anxiety, and leads you to perform "compulsions" in order to try and quell the thoughts. It's a repeating cycle that gets worse the more you feed it.
My experience, is that OCD can have you questioning every single "what if". Combine this with questioning romantic orientation.... it's a special Hell.