I just found a boatload of preteen porn on my husband's computer history?? what do I do? I'm freaking out!!!?

My husband is the sweetest thing ever. I am so in love with him, and he's been showing me the same. I never even thought he watched pornography to begin with... The other day I was at his computer and decided to look through the history and found so many pages of preteen porn and young girls who are dressed as pornstars!! and so many of these sites... And to top it off, the dates he's been looking at these sites we were engaged, and he'd look at them quite often... I am depressed, I don't know what to do... should I confront him about it? I am scared to confront him about it, because I don't want him to start deleting his internet history and messages and stuff from me. I don't want him to hide anything... I am so confused, what should I do?