This is similar to a problem i had. I used to always be afraid of laying down the best hand, and if i did it would boil me up inside. After that i was so afraid that i would fold a best hand and lose money i should have won, that any time i hada mediocre hand i was check calling all the way through. The fact is you have to ready and willing to fold the best hand if you seriously doubt your hand. If you have a lot of preassure on you and fold the best hand, dont worry about it. instead think about what would have happened if you have called and he had shown down the best hand. You probobly would have been one buyin shorter.

Dont go playing like a pussy, but also dont let it get to you if you do happen to fold the best hand. Just factor it in for next time, and remember that with the information you had, folding was probobly the best decision.