You have very beautiful hair. Looks like 3b/3c/4a to me and a lot of women would probably kill to have it, is my guess
You may need to alternate a protein-based conditioner with one like Suave Naturals Coconut.
Speaking of coconut, you might try using coconut oil as a sealer. But if you do, you should use regular commercial shampoo once in a while to reduce build-up.
The fact that you're in such a humid environment means there's only so much you're going to be able to define your curls.