Hi Hbombaby
So 'fessing all was something his therapist told him to do? On the one hand, the therapist gave him the opportunity to benefit from the inner un-hiding, which supposedly results from self-revelation; on the other hand, s/he has thrown the client 'on the mercy' of those who know him, thereby putting the client in a time-honoured apparent position of risk and 'gamble', and putting you and those close to him in the time honoured position of being expected to forgive, to be 'stern but nice', and to otherwise refrain from the urge to kick his sorry back door out of the front door.
It is clear that, by his admissions, he has violated principles which are extremely important to you. He has piled them on your table - on your plate in the same 'mouthful' as a PROMISE. It's a conglomerate proposition: "Hey I got this stuff to tell you -ewww-ewww-ewwww-and-I'mWorking to stop it and it's the only way You can get closer to Me and that's why I've told you and also my therapist told me to do it'
Confession puts Burdens and Expectations on the person being confessed to, especially if an 'expert' has, or has been said to have, advised it. You become responsible for being supportive or destructive to a repentant person's mission to redeem himself, to his course of therapy, and to his valiant struggle to 'let' you get closer.
Remember, though, the guy you actually wanted to be close to is a guy who would never have done this kind of shit to begin with. It didn't have to be about masturbating to pictures of your room-mate, or violating people's privacy, or standing with his mates sharing nekkid GF pics. It could have been about Anything ... anything which significantly violated your principles or crawled from those parts of the world which fill you with loathing and disgust.
My strongest concern here is that wittingly or unwittingly, he, having gained your trust, is, de facto, proposing that you redefine your entire basis for relationship, and that your getting closer to him REQUIRES your accepting that redefinition. It is entrappment, and leads me to two questions:
1. Are you now in an space you accept? IF, before you met him, you'd decided that 'Bad Boyz throwing themselves on your mercy then Turning Their Lives Around' were the kind of people you really wanted to be with, then he's Your Kind Of Guy. It's a popular theme of musicals and romantic comedies, and hopefully, the next few years of oscillations between hope and disappointment will be a fulfilling time. If this is a story you don't like the sound of, please refresh your sense of what you do want ... for what he SEEMED to be is what you fell in love with, and those qualities may be found in people less likely to make such heavy claims on your forebearance.
2. Is he an habitual surprise-monger or 'entrapper' .. are there other areas where he holds back while you 'notice but carry on as usual,' until he tells or shows you that Toto ain't in Kansas any more, and you and your Munchkins are going WTF! ? An ex-acquaintance of mine was notorious for offering people rides to important appointments and then making them late by insisting on running unannounced side errands.
If you've been choosing to stay with him for a while longer, beware he does not become what I'm calling here a Revelationist. A Revelationist is someone who has confessed at some point in his life, been forgiven/tolerated/endured, and has got the habit of Katharting. He secretly gets himself off on the expressions of upset in the faces of those he confesses to as he delivers those multiple guiltgasms and fall-from-gracials. Forgivurbation and sin-swallowing become a video-loop. He gets to do "Mea Culpa" but WE're the ones who actually get to feel bad most of the time.
As it is, your present story has already moved on a bit, and you may wonder: "It is more than a week since he revealed these things to me ..... now, regardless of how I feel about what he's done and not been telling me, is his having confessed making him a nicer person to be with? To what extent have his behaviors with me been changing for the better? To what extent am I feeling that we're close in the ways I wanted to feel before the distancing and subsequent revelation?" What, in the last couple of weeks has changed, what has remained the same, what is your update as to how you feel and what you think about it all, and what this all means in terms of what you're reckoning on going with it?

OH ... and by the way ... has he stopped doing that shit?
Take care.