Heartbroken but still want kids

I love my wife so much BUT that fact that she never wanted to grow up and be an adult drove to to demand a divorce. I found myself always having to make adult decisions alone because she refused to and always the one to make the decision against the "fun" stuff because we had bills to pay or money to save. We were planning a future together and now I find myself lost. I've wanted a child our entire marriage and after years of failed tries I am alone, still with a desire of a family. I don't want to be in another relationship because my heart belongs to my wife but what do I do to soothe this ache in my heart? Raising a child with my soon-to-be ex wife would be like having two children and twice the bills but damn she would be wonderful with a kid when she decided to come around and be responsible. She is in another relationship already and suggested we coparent... I couldn't ever do that to my child. I couldn't willingly set my child up to be born to parents that also hate each other or with one only half way willing to commit to being a parent. What can I do??