<human>: Can you summarize the given text in a few sentences?

**Background: my husband is MTF Trans, pre-everything and we are still using male pronouns. We have been married for almost a year**

5 days ago I found out my husband had cheated on me. His email was up on his phone when I went to use it and, on a whim, I had gone through his sent email (I am not proud of this) and saw an email exchange from craigslist (in November) that outlined meeting up for a blowjob (him giving the blowjob) and a following email that said something to the effect of "thank you for the good time." 

I immediately went to the phone and called him up at work, telling him off and asserting he come back to the room and explain himself. When he came back he admitted to blowing the guy, and said that that was it. No reciprocation. He said he wanted to do something that felt feminine, but didn't get the result he wanted. He feels bad about it and assures me that he is not attracted to men (not that that would matter to me, I like to reference the Kinsey scale when it comes to sexuality) and that it was a one-time thing and wants to stay married and that I am the one he wants to grow into a old woman with.

I want to make it work because I believe him, but I feel betrayed and insecure. I hate that I do not know for sure if this is going to happen again. How do I get this reassurance? What relationship-strengthening can we do? Did I make the wrong decision? I feel like I am drowning.
<bot>: Checked husband's email, saw an exhange for sex, confronted him, am wanting to make it work but this whole situation is causing me anxiety.