It's ok to cry right now, it's a shock and you will need some time to process it.
I wish I had more advice, but I don't know how to handle the A situation but you should have a look at some threads over on the Infidelity forum. Starsky in particular has a lot of good advice on how to handle confronting a spouse about an affair. Have a look.
Good luck and take your time to get through this. Don't give up your GAL and make sure you look after you right now.
Me 28 / H 28 M 1 / T 2.5 BOMB 12-3-14 "I don't feel like myself any more" Still living together, separate rooms.