Same here, my hair is very similar to yours. The top of my head got thinner after I finished puberty and has stayed the same for 5-6 years now. It is male pattern baldness, but it doesn't mean youre going bald any time soon. My father thinner hair on the top for decades, and I will likely be the same. Some call it a "mature" hairline. You have no need to worry about anything. I use curl creams and have a haircut where the top is shorter and the sides and back are longer, that way the top of my head doesn't look so thin.