Help please

I had been married for 6 years, been together with my husband for 13 years and I am 28 so practically half my life. We get along so great, never fought, like the exact same things, movies, music, vacations, etc. he is my best friend. However over the years of our marriage, we stopped having sex. I became interested in someone else. I never cheated but this prompted my divorce. I began to realize that my husband was more like a room mate to me and I found myself attracted to other people but not to him. He also has a son by someone else (happened during some time apart in our teen years) and I had to immediately be a mom to his child bc his mom isn't in the picture. This also placed significant strain on our relationship. My husband is very skinny and we got married young. I've realized with time that I am not really attracted to skinny men, And I know this is not something he can change. He would do absolutely anything for me and he lets me know this all the time. He so desperately begs me to come back to him even though we have been divorced a year now. I am dating someone else who is a good guy, attracted to like crazyyyyy, but we are very different people. I've been finding myself lately wanting to maybe give it another chance with my ex husband but I don't know if doing so would be the wrong decision because I made a very serious decision by leaving our family. I also love the man that I am with now but I'm afraid our differences will eventually tear us apart. He also seems very willing to compromise with me and wants to make me happy. I find myself missing my life with my husband sometimes but then am reminded that I left for a reason. If I go back to him, I can't help but wonder how I would have a child with someone im not crazy attracted to??? Anyone have advice for me or been in a similar situation? I think about this every second. I would appreciate some help.