I would begin by getting your other finances and legal sitch battoned down before I did anything rash. You've waited this long, what's a couple more weeks going to hurt? Seek out all the advise you can get, pro and con, about the various approaches and ask others what worked for them in their sitch.
Does your wife work outside the home? Who pays for what around there? I certainly wouldn't be paying for anything that actively (or even passively) enables her affair.
This is a great forum to get support, as is any of the "DivorceBusting" or "DB or Not DB" social media forums. Exposure is NOT advocated by MWD (altho others strongly advise it), so you'd better be prepared emotionally, financially and legally for the fallout if you go that route.
Hang tight, you can do this. My wife and I came back from her affair stronger than ever, and have since celebrated our 25th wedding anniversary, the birth of our grandchild, and the marriage of our oldest daughter. It CAN be done!!!
