We also did the tylenol before visits and nursed in the office right after the nurse left after giving the shots. I always just look right at my LO's face, and remind myself that he's taking his cues from me, which helps me keep from grimacing and wincing and instead smiling at him and telling him how brave and amazing he is.
Once home, we gently massage his legs to help prevent soreness and the dr. suggested doing warm washclothes on them as well if he seems uncomfortable. She also ok'ed another dose of tylenol before bed too, to help himthrough the night for discomfort and/ or fever.
It really does sound like your LO handles it well -- good luck tomorrow!