What should i do?

Sheena
So like 2 weeks ago I snooped threw my boyfriends phone (we live together been dating on an off for almost 9years were suppose to get engaged last month but I felt something wasnt right) while he was in the shower only to fine he was texting some girl he was having sex with that he knew when he was in school so anyway we argued n I was willing to stay only because I've done shit he has no clue about. OK so like wednesday I had his phone because mines was stolen n I had his phone for almost 2 weeks and no one has text or calls so I called him on it then as soon ad I put the phone down a text talkn bout how she had a dream and she don't think he the father I went sky high like when I say sky high I'm talkn me n GOD was sitting side by side so anyway come to find out he slept with her 3 years ago when he claim we wasn't talkn and he had the papers wit a court date and paternity teat date for almost a month n never said anything to me. So now I'm like OK wtf am I suppose to do hes like he's sorry they were having sex the condom broke n they stopped n he left. So now he's upset because I told him if the child is his I don't want anything to do with him since the whole time we've been together we have been trying to have kids and its never happened for us n I don't want any type of baby mama drama in my life I'm n a different place (sorry this is so long) I'm the type of person where if me and u r together ur child isn't coming to my house I don't want to share my attention that I get if its not my child. I'm so like beyond embarrassed devastated disgusted I don't know what to do.......am I over reacting? What should I do? What would u do? Help!