I have 3C curls and just bleached my hair and before I used a ton of coconut oil so the bleach could strip all that oil off and not much of the natural oils on my hair and also deep conditioned before and after. My hair still curls exactly the same and I believe it's from all the coconut oil since coconut oil causes your hair to hold on to protein and bleaching can break the protein bonds aka loosening your curl. I suggest not highlighting your hair and alternating between protein treatments and deep conditioning. Hope that helps