How can I motivate myself to get out of feeling betrayed when I found my husband inappropriately texting a business associate?

My husband and I have been married for 23 years and have 2 kids (26 yrs & 18 yrs). 6 months ago I viewed a text that my husband sent to a married female business associate. She works at a university and he at an accounting firm. They met through a joint entrepreneurship program that each of their businesses jointly facilitate. It was not an explicit text but definitely sexual in nature.

She did not try to deter but participated. It was five or six texts going back and forth. Once I approached him, he then guaranteed me nothing was going on. That it was just stupid fun. That he regretted the text (of course because he got caught is my feeling). From that point on they became more distant and more professional. Recently the firm he works for posted a job position for the program they run and she applied for the position. This upset me greatly. He promised she was under qualified and would not get the position. Then the day before the interview he told me she was the most qualified and that would most likely be hired. Their were 4 people interviewing her and my husband had influence but not the final decision. She got the job.

I think I almost lost my mind. I felt betrayed and unimportant because of the initial texting but now when he said she wouldn’t get the job. Then she got the job. My trust in what he says is gone. I feel he is only saying what he thinks I want hear not what he truly wants or believes. The job will bring her closer to him. He is her direct boss. They travel twice a year and he extends each business trip for the weekend. He goes to the city she lives in (more local) and stays for a week. (Oh my God as I write this I feel so stupid!) He has guaranteed me that I am most important. He won’t extend anymore trips….then just a couple of days ago he waivered on that as well and said at least for the next few trips.

I have had a tutoring session with Krista St. Germain who helped me to realize that I cannot go from betrayal to trusting him and feeling secure that quickly. She said it was like a ladder and to do one rung (or baby step) at a time. My husband would prefer that, in his words, “I get out of the mud”. Which definitely has validity but I am struggling. He is traveling with this woman next week to a program. I am not sure how many people will be attending, probably 15- 20. He did not extend his stay but he will be staying for two nights.

My husband goes from being supportive of me to getting angry because I am not changing fast enough. He said he would go to counselling with me then said he had an epiphany and decided he wasn’t going to go. He says he will prove to me that he is truly trustworthy. That he regrets what he has done. That me and our children are the most important thing in his life.

I want to believe that and I go from being strong and confident to being a crying puddle. I want to get out of these feelings and sometimes I am successful, other times I feel awful. Is this where I find my “compelling reason” and focus on that? I do not want my marriage to end and neither does he. We both want to come out of this as stronger individuals and a stronger couple. I feel as though I am failing and pushing him away.