1. Tell them, and risk losing them when they tell you they don't feel the same way (because that's always an option.) 2. Not say anything,because you're afraid of losing them completely, and put down the past 6 months of celibacy as "a novel experience" which, of course, has nothing to do with the fact you can't think of getting close to, never mind having sex with, anyone else but them. 3. Go out and get very drunk.
This, obviously, is an entirely hypothetical question. I'm doing research on human behaviour, you see. Answers welcome. Ta.