OP here - I wanted to thank y'all for the great advice so far, and I wanted to share one thing that has helped me a lot: founder's breakfasts.

We get together once every two weeks and hold one another accountable. I bring donuts. Everyone shares a good thing and a bad thing that happened, explains what they accomplished and failed to accomplish, and commits to what they'll complete next time.

One thing: it helps to make sure everyone in the room is at a similar stage, or at very least working on product-focused startups (or all ecommerce, or whatever). That way there's a lot more value in hearing what other folks are going through.