When I have dry itchy skin I apply a product called TriCalm to my itchy skin and then after using the TriCalm I apply a skin moisturizer and massage the skin moisturizer into the skin.
Try lowering the temperature of the shower water from really hot to a lower warm temperature because too hot of water can dry out your skin.
Use a gentler soap when washing your skin in the shower or bath and take some Vitamin D supplements as well as drinking plenty of water to keep your skin moisturized from the inside.