Really long. Need advice, can't talk to anyone else...

Ok, before I start NO NEGATIVE comments please. So I've been with my husband 9 years in April. Married since July 2014. I'm 22 weeks pregnant. He works away 2 weeks in 3 and I have been suspicious for a while. My suspicions and doubts proved me right and he had been texting this other girl. He just use to meet up with her at the gym and send flirty messages constantly. Well 2 days before he came back for good (also 2 days before OUR baby's 20 week scan) he booked a hotel with the girl, 3 course meal and slept with her! Left for work the following day and then came home to me that evening. I only found out Friday just gone that he has actually slept with this girl! Obviously I went mental. I know I'm a mug for staying but I really do love him so much, he is sorry, he has changed his number and is trying to make it up to me. One minute I'm fine and the other minute I'm an emotional wreck! I don't know many other people would stuck around and if the roles were reversed I think he would have gone by now. I want to stay and get our spark back so I need to stop throwing things in his face or asking questions as it's not helping me get over it. I feel such a mug but am choosing to stay. Please no negative comments, just want some advice on how I start to get over this and how to make it easier for me to deal with. Thanks x