betrayed and lied to

hi all...

a rather complex story here....bit hard to know where to start. been with partnerfor 5 years....i betrayed him and met someone else once, but he found out and i told himabout it. a year and a bit down the line, he then leaves me and our 2 yr old, and i am preganant with number 2 ...he says it coz he couldnt cope with it no more,,,but then i find out he was texting someone the week before he left. he was left for about 3 months, in that time he had met up with this girl lots if times, slpet together,,,but he claims that there was nothing going on. i cant help but think that he left for someone else and used what i had done as an excuse to get out to meet this other girl.....he came back when baby was born.....its hard going, all these things are in my head constantly, just wpndering if there any one alse who gone through this