I am so, so sorry you are here. No one ever wants to be here.
What you're feeling right now is perfectly natural. Your world has been turned upside down. It's said that it takes 2-5 years to heal from infidelity, and trust me, the first year is the hardest, IMO.
Have you read any of the articles in the healing library? There are articles your WH can read as well.
As for separation or divorce, you don't have to make any decisions right now. I would urge you to take a few months to make a decision, or longer if necessary. You cannot fix your WH, only he can do that. And it's hard work on his part, but it can happen if he's committed to it.
I mean this as gently as possible, but at this point it's possible, even likely, that you don't have the full story. On this site it's called TT, which stands for trickle truth. It when the WS lets the BS know the truth a little bit at a time. It's soul-crushing.
Hugs to you, keep posting and reading. You will survive this!
Trust is like paper. Once it's crumpled it can never be perfect again.