How can I undo the damage on my hair?

woah 20cm past your shoulders is long, I would never want to cut my hair if your school doest allow different hair color then they probably wont let you leave it open ryt? my school was like that you should leave it the way it is naturally now and then, it would save you time

you rather not color your hair and just wait till you finish school, then you wouldnt waste money by having it for a few weeks and covering it up

you should get a treatment done on your hair, to repair it go to a salon or drug store

maybe the product that your using isnt good enough I use pantene repair and protect shampoo and conditioner and lo’real hot straight heat protection lotion on my hair when I style it my hair is long and not damaged

hope I helped :-) take care

I think you should let your hair go natural for a while. No harmful heat or colouring for at least 1 month. Do weekly deep treatment conditioners to your hair (go to a salon or beauty supply store and ask for the best one for very dry hair). Then when you use it, wrap your hair with a plastic bag and then with a towel to keep your head warm…the heat is really important in the effectiveness of the conditioner. If after a few treatments you find that some areas are still dry, I would suggest to trim them off yourself if you are reluctant to go to the salon. I really think if you do this your hair will be well on its way to repairing itself.