I was in almost the exact same situation recently. My girlfriend of several years thought that homesteading and permaculture are silly and had less than zero interest in them, also she didn't want children.
Having a big homestead family one day is really important to me so having someone who is incompatible with that just doesn't work. I already have a small farm and off grid house mostly set up, she refused to even visit it with me. Depending on what it is you want to pursue and how flexible he can be, it might not be as big an obstacle as you think.
If you are anything like me, this issue is eating you up inside and upsetting you at a deep level. It was so traumatic to end the relationship but I feel like I have a new lease on life and I have been doing lots of positive things.
If you want mutually exclusive things in life there is no way around it. It won't be easy but you are not being fair to yourself or him.
