Taking your power back is one way to survive this. The heavy lifting is going to be his responsibility. Purchase the book "how to help heal your spouse" (I think that is the name, hopefully someone will give the correct name)
Be prepared for trickle truth (TT). Usually if the WS says we only kissed once - it is we only screwed three times. The WS minimizes bc they don't want to "hurt" the BS more. When in truth, the exact opposite happens.
If he is still working with the OW, one has to quit.
If the OW is married - tell her BS. They deserve to know
Tell their boss - why? It will keep the relationship from starting again.
Look for burner phones, apps on his phone, pull your financials - credit cards, credit reports (sometimes they take other credit cards out to finance the affair), bank statements and phone records. Have him write up a time line.
AP is to be blocked on everything and a NC letter sent.
Go see a lawyer - not to really divorce but see what your options are *SHOULD* you decide you can't R. Knowledge is power. In some states the AP can be sued for alienation of affection.
Read up the healing library, it really does help. Listen to the veterans on here - most can write a script for your upcoming healing almost verbatim.
Go see a Doctor, make your WS go too - check for all STDs. If he protests, tell him you have already lied and cheated on me and I feel the need to protect myself at this time.
Eat healthy, drink H20, limit alcohol, see a dr for medicinal help for short term stress (if needed), exercise, find a hobby - something that will take your focus off the A.
Ask him any questions you want, until you feel healed. Make him do the heavy lifting of repairing your trust. Repeat this "He made the choice to cheat, I did not nothing wrong". Because even if there were issues in your marriage he choose to cheat instead of talk to you or go to Marriage counseling.
Be prepared for the rage to hit. It will hit, and it will be rough but it is normal.
Hang in there, you got this sweetie.