Husband cheated with my close friend.

My husband and I have been married for over 15 years and we have three young children. We were high school sweethearts, and had only ever been intimate with each other. I recently found out that he had been having an affair with one of my close friends for six months. I found out because I went through his phone because I could feel that something was off. I am completely blindsided by this and devastated beyond belief! I’m so freaking mad at him, but I hate her with a fucking passion because I was confiding in her that I thought things were off between us and she just kept looking me in the face and telling me everything was going to be OK even though she knew she was behind it all. Our families had been hanging out together almost every week, and our children were close friends and now I have to try to explain to my children. Why we no longer can see those friends. As of now, we are trying to work it out, but I am still struggling after almost a year and hoping that I will again be able to trust and feel worthy. Leading up to this infidelity he has always been an amazing husband, and I never would have thought he could do this. I truly love him and want to make this work . If you’ve been through this or have any advice, please share.