You cannot reverse the problem.
What you need to do is keep it on your head ...More >
IT NEEDS TLC. It may actually mean having it cut to remove the problem.
What I would do is visit a good professional salon for advice in your area.
Having blonde hair and moving to a hot climate with hard water? Boy your hair needs help.
Seek some good local advice and follow the home hair care advice to the letter.
There are some professional ranges which have some fantastic treatments for Dry, damaged, coloured hair. Seek them out and you should start to notice a huge difference.