First, BREATHE.
Then eat, even if it is just a protein shake.
Then breathe some more. And reread your post.
Yes, you could have told him, probably should have told him, BUT YOU DID NOT CHEAT!
Period.
Do you really want to be in a vulerable position right now with being a SAHM.
Do you have enough saved up financially in case he cheats again or just walks?
First priority, get yourself together, then your finances together.
Did you ever see an attorney? If not, go see one and find out what you are entitled to. Better to hope for the best but be prepared for the worst.
Stop crying, you are in panic mode and cannot think straight when this happens, for him and stay calm. If you feel like you have no control, look at 180 again.
You have NO control over his actions and you are not to blame for them either. However, you DO have control over yourself.