Oh GR, how horrible for you. I'm glad you yelled at him - you won't be able to resolve anything by keeping your anger inside. The best advice I ever heard on this was from my Mum - my Dad had 2 affairs, but my parents are now very happy together, nearly thirty years on (they've been married 40 years in total). My Mum said that if you're going to forgive & patch things up then you have to be able to really forgive, not just bury your hurt and try to appear ok about it while not actually trusting your partner and feeling awful inside. So first you have to express all of your anger. If you still have any lurking mistrust, or anger and hurt that you haven't expressed you will never be able to patch it up. And unless he can prove to you that he's changed you won't feel safe again. So don't try to be forgiving before you're really ready to forgive.
Don't question whether other people think it's okay for their husband to be in sex chatrooms, or look at hardcore porn. All you need to ask yourself is 'did it hurt you' and it clearly has hurt you, and he knew that it would hurt you. This entitles you to throw all the crockery you possess at his stupid head - whatever anyone else's standards are, especially as it has been part of him actually trying to start an affair. You sound like the sort of person who tries to be nice, and tries to avoid a row, but that won't do you any favours in this situation. Get in touch with your inner hag and do some serious screaming.
Personally I would ask him to pack his bags and leave but to attend couples counselling with you to see if anything can be salvaged. Flowers certainly ain't gonna cut it! I'd make him eat the flippin' flowers... If he wants to get you back he'll have to win you back with some serious hard work and honesty. If he isn't prepared to put in the work it will take to win you back, then it wouldn't have worked anyway.
Sorry this is a long post. Btw, re: my Mum & Dad - I love them both to bits, but I have to say I have much more respect for my Mum, and I do think of my Dad as being a weak character because of his affairs. I wonder if your husband realises just how much he's given up?