Try to destroy the evidence.
Go to your wife first and let her know you made the biggest mistake of your life. This way you beat the mistress to the chopping block.
If your wife finds out, you may have hell to pay (literally....her being hell) in a divorce.
But, hey, you obviously do not love your wife, nor are you worthy of her love, because you have been cheating on her for five years. Actually, she probably already knows but is comfortable with her life and does not want to give it up, just like you. Maybe she has a stud of her own.
No, there is no way out of an affair unless she finds another guy and tosses you to the curb.
This, one day, will come to an end and your lifestyle will change. When that happens, just don't get remarried because then you can lead the single life and sleep with whomever you want without it financially impacting you .