Sorry about this. DON'T make any decisions or react right now. You are mad, and rightfully so.
Getting out with S for breakfast or whatever reason is a good idea.
You feel like you are back down b/c YOU still care - and that's ok. But, you should be proud of yourself - you stood your ground in a tough situation. Do you realize that? You played it well. Now, ball's in his court.
Sort through your feelings - don't fight them. Let them out - alone. Regroup when you are calm.
Also, once W and I began our problems, I put a password on my blackberry so she could not acces it. Always had that on my laptop. You should put a password on your devices. Next he snoops (and that's exactly what he did - would be a boundary issue for me as long as problems exist), and if he has the balls to ask you why (which your H has shown no shrtage of), tell him your emails/txts are your business right now.