Sorry you are here. Im sorry you are in pain.
Follow the above advice, especially reading through the healing library.
Also, review the 180D and the tactical primer thread please. You may need ithem later.
Ok, I dont know your situation, but I am one of the people on SI that believe that cheaters are the types of people that will continue to cheat or will cheat again. Based on their behavior, they should never be trusted again.
Based on my experience, what I have seen friends and fanily go through, and many many stories of the poor BS on this site, please be prepared to expect anything and everything. Prepare and protect yourself.
What he says was two months may have actually been a year. "We kissed only 3 times" may mean they had sex 50 times.
My wifes alleged 3 month A with only protected sex 3 times, turned out to be a 1.5 year affair with more sex you could ever imagine. Unprotected sex, oral sex, possible STD, they even went on an out of town trip together.
Be prepared for TT and gas lighting.
Eat and get plenty of rest. Most importantly, TRUST YOUR GUT.
You do not have to make decisions now, but do not take this lightly. At least consult with a lawyer.
Do not let him screw with your head. People like him do that very well. Do not tolerate blame shifting.