My dad is a NW7 too. Your hair looks good for now. Yes, I feel a hair transplant doctor that is reputable would be the best choice to evaluate your hair as long as they have tools that do it. I don't think dermatologists are as educated about hair loss like a hair transplant doctor. I have taken finasteride for over ten years and it did not stop me from getting worse but I only got slightly worse. I am more of a diffuse thinner too. However, I am sure I am closer to your dad's age if you are 19 so I got really lucky because my situation was like yours at 39.