Maybe try a coconut oil treatment.
Warm up some coconut oil in a saucepan, add a few drops of essential oil if you choose, a vitamin E pill if you choose, ( pierce with a pin and empty the capsule into the pan ), warm gently.
Massage into your hair, from scalp to ends. Leave on for a good hour, more if you have time, with a plastic bag over your head. I did this all the time in the days when I dyed it.
Hope this helps you.