Cheating and lying

So.... first of all I am very nervous to post on here... please only respond if you have been through a similar situation.
It started in 2014... my wife connected with a friend from high school. She was 41 and was really enjoying talking to her. I didnt think anything of it. Then we started fighting a lot. She got very defensive and depressed. She had been turned down for a promotion that should have been hers. I tried to be supportive but there wasn't anything I could do. I asked her to see a doctor as I am a nurse and thought she needed help. She refused. The fighting got worse and I started noticing she would put her phone face down. She was always talking to this other woman. I started getting a gut feeling something was off. I asked her what was going on and she would get pissy and tell me that they were just friends. I told her i was uncomfortable with how much they were talking and she blew up at me. So, I looked at the phone records and saw on an average day they spoke 12 times on the phone and over 1000 texts. I was not feeling good about this and talked to her again. She flipping out, yelling and screaming. I found a marriage counselor and asked her to go. She agreed. She told the marriage counselor on the first day that I had jealousy issues. We went to 3 sessions before I had enough. All we ever talked about was my so called issues. She sat back like she didn't have a care in the world. A few weeks later she broke up with me. It was a week before me sisters wedding so I asked her to go a with me and our 2 kids. She said she would think about it. Meanwhile she never left our house. We slept in the same bed. She cuddled me and still kissed me. Nothing changed. Then someone posted to her face book that she was proud of her and loved her so much and couldn't wait for their future together. I confronted her about this, it was only 2 days after brake up. She said she didn't know that person and immediately deleted her. She comforted me and told me she just needed to find herself and didn't want to be with anyone. A day before the wedding she told me she wasn't going and was going to see her family while I was away at the wedding. When we were both getting ready to leave she held me for a long time and kissed me like she loved me. I could feel it. I was so confused. I didnt talk to her that night. The next morning she called me crying saying she loved me so much and needed me and they kids and how sorry she was. My heart was full again. We talked a lot over the weekend. We got home and then she said we weren't together and she was confused. About a month later we were back together. Over the next 4 year she broke up with me on and off. But never left. Once I had found a new place to live with the kids and she immediately told me she loved me and didnt want us to go. I took care of her after 3 surgeries and took care of our family so she could spend 4 month away taking care of her sick mother. Over these 4 years this girl came in and out of our lives. She knew I didn't like it and would consistently lie and say they weren't talking. I would always find out they were. She always told me it was harmless. We would fight and she told me she would be damned if she lost a friend over me. I told her if she was going to talk to her, I didn't want her talking about our relationship. During this time the girl would make up fake profiles on FB and leave her little messages. She befriended our good friends and would comment on stuff I was tagged in. She even called me at work and told me my wife vents to her about me all the time. Finally in 2018 this stopped. I didnt know why but I was happy. Our relationship improved dramatically. Fast forward to June 2020. We were casually talking and I told her that I had always felt like they had and emotional affair. I didnt think anything else because she was on the east coast and we are in Texas. She asked me if it would help me to know the truth. I said yes, I wish I hadn't now. So, apparently in 2014 they were in a relationship while we were together. She said she was in love with her. She had met up with her twice and once was the night I left for my sisters wedding. I was devastated. I never expect that. It is not only the affair affecting me. Its her treating me like crap over the next 4 years and her still talking to her constantly. Not to mention the counseling sessions of me being told I need to work on my jealousy issues and my gut feeling was wrong. Because they were actually in a relationship at that time. Over the last few months things pop in my head constantly. Im a very visual person and I see them together. I shake because I'm so upset. If I try to talk to her she gets so mad. Less than a week after I found out I tried to talk to her she told me if I was gonna bring it up every 2 days she was going to divorce me. Then came back and apologized a couple hours later. A month later I needed questions answered and she screaming at the top of her lungs at me. 3 weeks later I tried again. She says I bring it up all the time. And that its the same things over and over. That I should be over it by now. And that me bring it up was putting her back in that depressed state of mind. Ahe says that was in the past and we have been happy for the last couple years and i should be looking forward. She has changed a lot and I dont want to leave, we were so happy before this. But my trust is gone and I'm falling apart and can't ask questions or talk to her. I fell like she still talks to her in hidden apps. I have seen her texting in something I dont recognize. Oh, also did I mention the other girl was married too. And now she isn't anymore.

I know this is super long so if you read this thank you for staying with me. I just dont know what to do. We have been happy and it is in the past but it was 4 very hard years for us. And what if she gets depressed again, is she going to go back to her or to someone else. She says she chose me after the physical affair but they were still emotionally involved. She said she never had planned to be with her. I asked her what she loved about her and she told me she loved that she had nothing on her shoulders when she was with her. I dont see that as loving her. I see it as loving who she was when she was with her and it could have been anyone. She agreed to that when I asked her what she thought. I just feel like all that time I was not good enough and I just dont know how to get over this and thought it would help to talk to people that have been through it.