Those messages about "not hiding behind your kids" are always unsettling. I found parenting so much more unfulfilling until one day I sort of woke up and realized that sequencing is okay. Everything is temporary. These kids will only be little for a short while, and right now, for me, the right thing to do is include them in every aspect of my life that I can because later, at a different time, our lives and needs will be totally different. Someday, I can work full time again if I choose to. Someday, I'll start exercising again (when DD2 starts kindergarten next year, it's GOT to happen!) Someday, I can write a novel. Someday, getting my hair cut and shopping for clothes for me BY MYSELF might be more important. But right now, I've got to embrace my life with young children and let my life be centered around them. It's still a major struggle sometimes to see the joy in "living in the moment" when at the moment my daughters are whining or fighting or bugging for the 15th time in two hours for a junk-food snack, but I do find that reminding myself that this is the right life for me TODAY really helps keep things in perspective.
That said, 5:30 sucks. It is the hardest hour of the day, and I remember it being particularly awful when my DDs were younger. We gave up on a traditional-style dinner for a couple years--with DH working nights, me working at home, the girls being hungry all the time and not wanting anything like a real meal for dinner, we just skipped trying to make dinner. The girls snacked or we took a light picnic to the park, we went for walks, I let them play in the bathtub while I read a book nearby. Just whatever made them happy. Because I found that if they were happy, I at least was calm. Then I'd make something DH and I would like for a late dinner--sometimes at 9 o'clock, after the girls were in bed, there we'd be, having a relaxing dinner. And now that our DDs are older, we can all make and have dinner together. It just wasn't the right time to have a family dinner when they were littler. WAY too much stress to add to an already difficult time of the day.