The first time I attempted a workout postpartum, I was an absolute sobbing wreck. With every yoga pose, yet another tear fell onto the hardwood. I felt so monstrously guilty that I wasn't tending to my baby's every need. Another night, about a week later, I passed my baby off to my husband so that I could sink into a hot, relaxing bath. But I sat there soaking in the quiet, too anxious about the guilt that consumed me for leaving my baby for a few minutes that I couldn't muster even a semblance of relaxation and pleasure. I have since learned that taking respite on occasion is an essential ingredient to my emotional agility as a mother. And the more intentionally I permit myself to recharge and nurture the parts of myself that have nothing to do with being Mommy, the greater the reunion with my baby girl will always be at the end of every break.
So do your best to turn your back on the guilt, now and forever. Nothing productive results from it, and taking time for yourself will always be a vital ingredient in the success of your family.