KEEP your ring ON
Do NOT separate.. fight taht at ALL costs
IGNORE her taking her ring off... she wanted the OM.. its a sign of an affair
I reccomend a different technique calle Ghandi.. its on this forum a fair bit, i will add more later...

Do NOT talk about your marriage with her right now... give her space to process you challenging her affair... but do NOT allow the affair to happen.. get in the MIDDLE of it as MUCH as you CAN

Make sure EVERYONE knows you caught her lying and ask everyone you TRUST to keep their eyes on her.

Do NOT talk about your feelings right now. Do NOT talk to hr right now about anything except your kids (if any)

Give her some space, but do NOT let her go near OM at ALL... do NOT trust her, but do NOT bother her either.