Pregnant newlywed needs hope!!!! I have a cheating ADHD husband.

First off, I truly want our marriage to work! We have been together for almost a decade and married for half a year. I'm pregnant with our first child. Just found out he had been calling and texting Craigslist-type sex ads. This isn't the first time (2nd) and there have been other trust issues as well. I don't know if it ever progressed to more than phone calls and text. He is undiagnosed but now has an appt to be tested. We are going back to couples therapy. I really need hope from other couples who have survived from infidelity. The worst part is I am going through so much stress and can barely eat and I'm afraid its hurting our unborn son. PLEASE PLEASE give me hope!!! My husband and I are best friends and we have made so much progress on the parent/child household chores issue which was a big problem before. I know we have our issues but we also have so many amazing things about our relationship and now we are starting our family. Please let me know how you made it through so it can help me keep faith that we can too.