My hair's always had that curl pattern, with the straightness at the top, and I've always had curls so I'm not in the same boat there, however I think my hair is definitely losing curl as I get older (I'll be 50 next year). It's also getting thinner and has been for some time, so I'm going to ask about it next time I'm at the docs. It's frustrating as I spent most of my life not knowing how to look after my curls and not having products to use, and now I do and I have my hair's getting less curly and just less generally.
Sorry, no help but I understand what a pain it all is.
3b in South Australia.