trust your gut and not your heart. check on the information. you will drive yourself crazy not knowing. and you deserve to know the truth. i hacked into my husband's email account because my gut told me that there was more to the story as well. i was scared just like you. but i overcame that fear and did it anyway. i knew i was going to find something and did. i dont regret not doing it, because now i know the truth about him.
you can never really count on a cheating spouse to give you the truth on their own. they only usually come clean once you have the evidence that cant be disputed.
i wouldnt say a word to your husband until you have done your investigative work and have all of your ducks in a row. then show him what you have.
in my case, what i found were dirty pictures that the ow sent to him. and another one of him and her on the beach...all cuddled up and kissing. i sent them to him at work attached to an email that read..."look what i found."