Break Up Blues

Hello all, so I recently broke up with my SO os 1.5 years. He is 40 and I am 25. He has one kid who is 8 and I had a pretty good relationship with him and his mother. My SO and I had a great relationship and I was even given a promise ring for Christmas this past year. I just finished college and have a Masters Degree in Education. I landed my dream job a few weeks ago. He has been there with me almost my entire graduate degree. Over the past few months we had been fighting more about silly things and he's been wanting me to move in and begin the next step of our lives together. However, I did not want to move in because we have been fighting and I didn't feel love from him like I used to. I broke up with him a week ago and I am just now finding myself missing him and our days together, our inside jokes and our good morning texts...among other things. We are very similar and never back down during our fights, leading us to say things we don't mean andhurt each other in the process. I'm having trouble recognizing if I am missing him or the thought of him. What do you guys think? Have you ever been in my situation? I feel like we had a great time together but I am just starting my life and he is ready to settle down and begin a family. Why do I feel so crappy for breaking up with him.....sorry this is so long :(