Will someone, for the love of god, slap this woman? She's talking nonsense! If you really feel this way, tell him, for god's sake, all this does is cause issues between you and knowing the guy. he would shut these feelings down in a heartbeat. theses feelings of doubt are nonsensical, and what matters is that you're both happy.
Seriously, if I were this woman's therapist, that's exactly what I'd do and then charge her 500 gold pieces. Yes, I actually would. For real, tho, telling him is a lot better than doing this to yourself.