Dry and itchy scalp

Okay, so recently I transitioned from shampooing every other day to only shampooing once a week. And my scalp is sososos itchy! I've been doing the once-weekly approach for about two weeks so far. Before, I shampooed every other day with a silicone/sulfate/dye free shampoo and did a vinegar rinse as conditioner. I'm still doing the vinegar rinse daily, and using the same shampoo about once a week. Has anyone found a product or a way to soothe an itchy scalp between shampoos that's fairly natural and organic, and without all the harmful chemicals? Or is this something that my scalp will get used to over time?