Hi nolly and welcome (officially) to SR. I'm glad you decided to post.
I truly empathize with your desire to have children. I remember feeling the same thing when I met XAH. Before him, I didn't want anything to ruin my precious body, but after falling for him, I thought that he was a perfect father figure. Little did I know that the show he put on for me was a way to sucker me into his life. During our 6 years relationship, he was the one who asked me for children, but he did it so he could keep me with him. When I finally did give in and have my daughter, he turned around and told everyone, including me, that he never wanted another baby, and that since I "forced him into it", it was MY job exclusively to take care of our child. He also used our child as yet another excuse why he had to drink...
I see that you already realize your partner isn't father material. I'm so glad you've come to that realization instead of trying to force the issue and finding yourself coming back to the board a few years later, having to co-parent with a woefully inadequate former spouse and partner.
I think the last line in your last post is very honest and telling "No matter what I do it is never enough"...This is definitely not a person you want to bind yourself to...
As for that ticking biological clock, I have quite a few friends who became SMCs (single mothers by choice) and have never looked back. I know how strong that drive is, and I hope you realize that you do have other options.