Yes, I agree with taking some time. If you don't feel ready to talk to H tomorrow, don't. If he has to sweat a little before you'll talk to him about this - fine. He should sweat.
Now - what I am going to say next = please understand, I am NOT talking about the chances of you reconciling. You have four kids and history and reconciliation may well be in your future.
BUT - if it is - do NOT make the mistake I made, of taking him back too easily. IF he is remorseful and wants to work things out- MAKE HIM DO THE WORK! Make him get counseling, go to Sex and Love Addicts Anonymous, if you think it fits, make him give you total transparency on finances and computer (so that things like "extra" cell phones won't be possible - unless OW pays for them, I suppose).
And yes, you may well decide that you can't trust him. A year long internet affair, and a secret cell phone for a second affair - that's a LOT of betrayal, ongoing, deliberate betrayal. But give yourself some time to breathe, don't make that decision in haste. The impact on the kids is too great - give yourself the opportunity at least to say you did everything you could.
But that "everything" does not mean leaning over backwards and being a doormat. It very well may mean standing up for yourself and insisting H does the hard work of growing a pair and facing up to his bad behavior.
