Mutually separated after being together for 8 years

My husband and I were together since high school. He was my first everything, the only guy I’ve been with and I have a lot of love for him, but we figured out that we’re not right for each other. Unfortunately we didn’t figure it out until after we got married, which was 3 years ago. We have a 2 year old daughter so the split has been pretty cordial. We decided to remain friends because we can’t be enemies or strangers. It’s just so weird going from talking to someone 24/7 everyday to nothing.. just calls here and there so he can talk to our daughter. I know it’ll take time to heal but I feel like he’s already moving on and honestly it hurts. Like right now, idk where he is or what he’s doing. I called him to say goodnight to our daughter for bedtime like we do every night but tonight he said he’s out and he won’t be home for a while. Idk why but that stung a little bit. And it kinda made me feel like our daughter wasn’t a priority for him at the moment which did upset me. Am I wrong for feeling this way? And I feel terrible because I’m struggling with school, and being a single mom (I have our daughter a majority of the times. He sees her for only a couple hours on the weekend) while he’s out doing what he wants whenever he wants. I guess that’s how it goes when you decide to split up so I’m “asking for it” but nothing about this is feeling okay to me and I don’t know what to do.