During our attempted reconciliation, WH was telling me about his epiphany... how while he was dating 2 different girls he realized that he could have just had the life he was looking for with me... so he came back to tell me. And I was really upset. DATING? In 2 weeks of moving out, while we were married and I was trying to figure out which way was up... he was serious dating??????? I got so upset, which of course was the wrong response, he wanted me to be happy!!??!!
You have every right to be angry, sad, and everything else you're feeling. It's the normal reaction to what he just did. Don't let anyone tell you otherwise, you are sane, he is acting insane at the moment.
Take your time, and keep him AWAY, find any reason you need to, even if it's just for a few days.... until 1) you feel stronger, and 2) he gets a slightly better emotional grip!