Cheating

My boyfriend of 4 years started cheating on me soon after first baby was born. Nothing physical. Depressed. Emotionally. Confused. a FTM. I tried for 6 months but I couldn’t handle. I hated him so much. Couldn’t stand to look at him. Hated him touching me. Was not in love with him anymore. I started talking to my ex. Just a week after talking he came to see me while staying with a friend. We slept together and it felt so good. I felt so comfortable with him and even do this day I dont regret it. My boyfriend found out I was talking to him. Never mentioned sleeping with him. But we’ve both been working hard on this relationship ever since and doing really good. I feel so guilty about not telling him. But even more guilty for not regretting it.