In a very weird spot

My fwb and I were doing good for awhile until I decided to keep a secret from him. I honestly never wanted to lie to him. I just had no idea how to tell someone that I am just sleeping with this secret. I was trying to find ways to until he found out on his own. He wasn't too mad. It's not that I slept with someone else or had an STD. It's something totally different and I'd like to explain it on here but I just can't. I really care about him although he may not feel that way for me. I felt sick to my stomach after he found out. Not because he found out, but because I lied to him and I didn't tell him myself. We talked and I apologized and explained it to him. I even messaged him after meeting up with him to apologize again and I told him it would probably be easier on him if we quit talking. He commented on the talk we had and said that if that's what I want then okay. He isn't the type to force anything or be overbearing. We haven't talked in two days. I don't think he will message me first after I said we should quit talking but I don't want that. I just felt I betrayed him is all. I don't want to be overbearing towards him too so I don't want to be the first to message him. What should I do in this situation?