I've waited to figure out how to put this somewhat diplomatically or tactfully, and I can't seem to do so. I'll have to settle for blurting things out, tactlessly and clumsily.
I fear that your M really needs to grow up.
Disclosure: it reminds me in a few ways of my X-M, so no doubt there is some projection here.
I was married for 17 years. We never had kids. I put X through school, we worked a bit, I went back to grad school. Mostly we were living a grad student lifestyle, especially socially. The parties, the going out to bars. X played hockey (a cost that was dear rather like your H's race cars).
Our R was stuck in adolescence, and it couldn't withstand the growth that it would take to move to the next level. That M could only last as long as we continued to live as children in some ways, because for each of us maturing into more adult versions of ourselves took us in different directions. But an adolescent R eventually becomes tedious, empty, unfulfilling. We start to want more from life somehow. Something deeper, more meaningful. For me, I finally decided we needed to have the kid that we were going to have when things were finally all in place. Putting those plans into motion was probably the catalyst probably for the end of the M, but not the cause. The cause, like I said, was that the M couldn't hold up if we grew as we each needed to, and it couldn't hold up if we stayed stuck in an adolescent R.
My new M, while much shorter (3 years now), is much more grown up. It is only from here that I can even see the contrast. What is different? Well, we're grown-ups lol. Turns out I finally became one through all the D crap. H had his own D to deal with. (We were both separated and getting D when we met, btw, very far along in the process, both emotionally D.)
We were grown-ups when we met, we were capable of bigger things, deeper partnerships. We had a wonderful fulfilling R before adding a baby, and the baby adds so much that it is hard to describe.
Now, to be clear, I don't judge you at all for not having a baby. For many, many years I was at best ambivalent about having children. I think you and H can have a good life without kids.
But I sense in your R that there is a bit of stuckness in an adolescent R. Where is the something more? Where is the bigger life project at the heart of a deep and loving partnership? Where is the greater appreciation that comes only after the big stuff (the really deep pains and joys in life)?
I think you are closer to being there than H, largely because you've protected him and sheltered him quite a bit through this process. He didn't experience the wrenching pain of what it would really be like to lose you. This isn't to suggest you should punish him, it is just that I think you are a bit ahead of him here.
Anyway, things are going so very well for you. I think your M shows great promise. I want you to be happy, I want your M to succeed.
And sometimes I get a sinking feeling because I see too much of a fun simple life that is somehow missing a big push involving something of great importance that will take you to the next level. I know that is vague, I don't know how to describe it any better than that.
I just don't want to see you M at risk in five years because one or both of you are asking: "Is this all there is? There must be something of more substance that will make life more meaningful." I don't want one or both of you primed for a disasterous MLC.
Are kids the answer? Well, I under NO circumstances think that one should have kids to improve an M. I also DO NOT think that kids are essential to having a wonderful, strong, grown-up M. Truly.
But in your words for some reason I see from both you and your H that you are ready for the next big step toward a big-picture life-fulfilling M, and maybe that step could involve kids. Maybe it is worth thinking about again. Maybe it is something you want but are scared to want or scared to admit you want.
So that is why I asked when you last talked about kids.
As for your health issues and children, from my limited experience it sounds to me that nothing would stop you from having bio kids and either using a high-risk doc or a surrogate. BTW, I had to use a high-risk doc. Not nearly as scary as it seems, it generally just means they like to manage you extra closely.
I guess the simplest way to put my point: find something big, shared, and of incredibly deep significance to add to your M as a fulfilling partnership. Maybe that is a child, maybe it isn't.