My husband began an affair when I was sick. I am SO scared it is a trigger I won't go back for treatment.?

Wow my heart goes out to you. I hope you are doing better physically. My only hope is for you to convey your fears and worries to the counselor and if they are worth any grain of salt they can somehow convey it to your husband and help him deal with and why he did what he did. My only advice to you is to stay with your treatments and give it time with the counselor and hopefully work on your marriage.