Cheater!

I am 34 weeks pregnant with our 4th child and i find out the man i have been with for over 9 years is cheating! I am hurt i am angry and cant even stand to look at him. I havent even been able to tell him that i know because i dont want to have a big blow up argument because its not good for me or the baby. And all he will do is deny it anyways. What do i do? I just feel so broken and like something is wrong with me