Cheated on by my boyfriend of 11 years

I'm writing to ask if someone has gone through this or something similar and if so, what did you do? I've been with my man for 11 years now and I have 3 kids with him. They're ages 10, 8,, and 2. Ovee two years ago when I was 7 months pregnant he started cheating on me with a coworker, that was May 2015. I didn't find out about it until a year and 10 months later which was March 11th 2017, a day after my birthday..💔 I did have them feelings where I felt he was cheating because his showers got longer and he started clean shaving a lot more and I noticed he was also shaving his pubic hair. He started wearing nicer clothes and left the house smelling like a whore house, which he had NEVER done before. I would say things to him like, I know your cheating, or, if you're and want to talk and be with someone else tell me so we can end this now. His response was always no. That I was crazy because he has his family and he would never do something like that. Well we didn't have sex much that should have been a red flag for me. I was pregnant though so I dismissed it. Normally during the six week recovery after a baby he would have been trying to do something with me but no he didn't. Now I know it's because he was getting it from someone else. Fast forward to January 2017 when I looked at his check stub which is what I should have done all along, but I didn't because I trusted him. He had taken off and used his vacation hours and I noticed his check was way to small that week for the time that he was gone and supposedly at work. I said to him I know somethings up and asked him if he had anything to say. He said he came home. Which is a lie. I said ok, I'm calculating your hours from here on out. He had gotten very angry and upset. Asking. What am I a kid to you. My thoughts were no, but your hours are off, and if you have nothing to hide then why are you so upset about it. He still took an hour to come home a couple times or one time some weeks and we had big arguments over it. I threatened that I will be watching him after work when he least expects it and I will find out whatevers was going on. Which is what I think is the reason he ended things with his mistress. This was the end of February when he called it off with her. So about 6 weeks after I found the hours not right and started writing them down everyday. His mistress was upset and texted him on March 11th at 1 in the morning and I asked him who was that and he was silent I asked to see his phone and there was no message. He deleted it. Boy did we argue that night. He had no expiation for the deleted message. But I knew it was a woman. And why delete something unless you're trying to hide something. The next day I looked at his phone again, and sure enough there was a number a missed call at 1 in the morning, well it was a answered and hung up phone call because it was a 1 second duration. I said ow yes I found it. I said the number aloud and his face was like he had seen a ghost. I called her right away from my house phone. She answered and said everything. They had sex multiple times over the almost two years. My first question was, Did he use a condom. Nope he didn't. Eewww I was disgusted. They were having sex in my car after work. He would pick her up and take her to work. He would tell her he loved her. The jacket he would wear that supposedly his work gave to him, no. She gave to him. She lives in the same apartment complex as me. Unbelievable right?! And she was putting everything out there because he promised her that he was leaving me to be with her but called it off with her and she had already told her man that she was leaving him for another guy, because that was their plan. Was to be together she said. She wanted to get back at him for lying to her and of course I'm sure she loved (loves) him. So many things went through me. Sadness, hate, lonely inside, empty, I couldn't breathe for a moment. I still get like this at times. Everything was sinking in and my gut was in knots. Heartache I never felt before. I never knew my heart would really hurt. I could actually feel the pain. He was pleading he was sorry, he cried to me. But I feel like I can't and will never forgive him. I still love him but not the same. I think I hate him more then I love him. Which is so sad to me because I hoped for him to be my one and only forever. As memories come back to me from when I had suspicions, it's like an over and over never ending thing in my memory. He came home sweating through his shirt and blamed it on a hard day at work. More like a hard after work. I hate him for this I really do . How could he do this to me. My heart will never be the same. My trust will never be the same. He even had me buy him from the store, a birthday present for his girlfriend, which I didn't know at the time. It wasn't until after finding out and thinking about everything and remembering the girly alcohol bottle a few months back he wanted for his guy friend at work he said. He was gay so I didn't think nothing. When I did ask him who was that bottle really for, surprisingly he answered with the truth that it was for her. The other girl. Ugh. I'm heartbroken! I don't know what to do.