DH and were married for 8 years before we had kids, and were really close. And I didn't realize how much had changed until recently, when we each wrote down our vision for our lives in five years, and mine included things like, "cultivate couple friend" and "cook with DH" and "develop shared hobbies." In our case, it wasn't so much that I was 99.99% focused on the kids (because I'm not), but it was more with three kids, three dogs, both of us working full-time, and his being gone a lot for work (international travel), we just do a lot of "divide and conquer."
For us, doing every day things together now that the kids don't require such constant supervision is helpful, things like grocery shopping together, cooking together, gardening/yardwork together, rather than having your own "domains" all the time (not saying you do, but it's easy to fall into that as long-term couples). Recently, we started going to the gym together before work, and though we go our separate ways while there, just getting there and back together is a few minutes of togetherness at the beginning of our day that is nice.
I don't have a lot of other advice, since we're just finding our way as well.