Would you stay w/your husb. in this situation?

First of all, I love my husb. very much. Last year he cheated on me after 9 years of marriage. He fell in love w/this girl. I moved away from them both to keep myself out of trouble. Making a long story short, we ended up getting back together, my husb. and I. We were only seperated for almost 5 months. In that time, this girl got pregnant. My husband is the baby’s father. I did not know that she was pregnant when I came back to him. He “forgot” to tell me. I found out 3 months later from HER boyfriend. Now he has to pay child support and go through all the bull that comes with his stupidity from not using protection. Everyone tells me that I should not worry about this because we were seperated when he got her pregnant. NOTE”” We would not have seperated if he had not been seeing her behind my back and in MY OWN HOUSE while I was out of state. One more note: While we were seperated last year when this occured, I had a mental breakdown due to a lot of reasons–but mainly this one. I stupidly attempted to take my life,, by shooting myself in the chest with a 380 magnum pistol. Thank God I was spared my life that day.
Will someone who is a third party to this situation please give me their opinion on all this,, I am slowly going crazy it seems.