My hair is severly damaged from gel wraps and wigs, how can i treat it for regrowth and thining?

i have worn weave glued in my hair for years and when i wasnt wearing a weave i was wearing a wig. EVEN MY NEW GROWTH GROWS UNHEALTHY. my scalp is always extremely dry and the front of my hair and the edges are the worst for thining and bald areas. what can i do to start my hair back to growing healthy?