If she is not changing.. You can file for divorce from her.. And It will take couple months to process.. And then you can be free as eagle..
Affair during marriage can hurt big time... You don't want to feel all the pains and depression, the best for you to deal and learn to move on with your own life where you can be happier.
How to get divorce paper - go to courthouse, and ask for a divorce paper, and it probably would cost 35 dollars to get the paper to fill out and turn in to file... If you have a lawyer, it will cost more, you go see a lawyer and ask for a divorce paper...
If you have kids with her, it is going to take a while.
I have been there and done that...
Again, I am sorry about the breakup.. It's tough. I can feel the pains... But for the best, time to move on and you deserve to make yourself happy...
