Still in love with someone

I’m in a very healthy relationship, but it sucks because I’m not in love with them. They have expressed that they want to spend the rest of their life with me but I don’t feel the same. I’m still not over my ex. He was definitely my first love. I feel so guilty for breaking up with him but I knew if I wasn’t in his life he would be able to grow as a person. He had become too comfortable in life and he was unemployed for a year and a half, didn’t have his license, and just couldn’t move out of his mom’s place. I was always paying for him and taking him places and at times I felt like his mom because of how much I did for him. He was also gaining weight and I knew he was unhappy with himself. I knew that if I left, he would be able to focus on himself. I was with him for two years and it’s been a year since we split. I felt this urge one morning to check up on him, and texted him. When he had told me how he was I felt so heart broken. He was everything I wanted him to be in our relationship. I feel selfish for even having these thoughts, but my being is yearning for him. I keep asking myself if I had just waited a while longer I would be happy with him. I know I have no right to be with him after how cold I was after our breakup and how quickly I tried to move on by starting another relationship. Knowing he’s in a place I’ve been waiting for him to be in, it hurts me knowing I’m not able to share that joy with him. I wanted to be the one to celebrate with him, but he’s with someone else. I truly am happy for him, I just feel so empty with my partner because I don’t feel that connection with them. I’ve blocked my ex and he has blocked me because we still are not over each other. I keep hoping to get back with him in the future but I’m impatient and I keep overthinking everything.