I'm so sorry. And at the same time this is what you needed to know.
The advice here is hundreds of women saying exactly the same thing.
You're staring at two open doors.
Pick one and you go into the future head up, self respect intact.
Pick the other and you're looking at decades of knowing ...
He cheated.
Possibly used a prostituted woman.
That can become an expensive and risky habit, as well as cultivating a vile attitude towards women.
If you have children, this will impact on them.
If you ask him about what you already know, he will lie, 'it was for a friend, honest...it was a spam email ... a scam ...' to keep things as HE wants them, to save face and his image.
That will then be the pattern of your life.
Cheat. Lie. Spend. Risk. Habit.
Disappointment, distress, forgiveness 'because I'm in too deep now...' til next time.
Consequences for your own and your children's health, happiness, mental health. Your family finance.
The dick-first mentality - will you enable it, or will you say no?