You need to stop, take a deep breath, and focus on YOU. YOU are the important factor in this equation, NOT HIM NOT HER NOT HIS BULLSHIT.
You have ZERO control over him or his actions. You DO have control over YOU. Take a moment and think about that. It's all about YOU.
The rollercoaster is normal. It takes some time. The first four or five months after Dday #1 I was a dazed fool, existing in life instead of LIVING my life. This last go round I found out on the weekend of the 4th and started dusting myself off a little over a week ago.
But the key ingredient is YOU. How much head space do you want to give him? How much control are you going to allow HIS actions dictate how YOU feel? You didnt create this shitstorm. HE DID.
Don't be so hard on yourself. Pick yourself up, call a friend or two and plan a night out. Give yourself time to heal, it does take time. But reclaim your life. You can do it.