I'm not sure if I should only get a hair transplant on the crown of my head.

As I age, my hair becomes thinner and falls out, and my crown is gradually becoming more empty. I feel very upset and stressed, and I am depressed. I look much older than my actual age. I thought that if I could just have hair transplantation on my crown, it might be a solution. Is that possible? It’s not very obvious, but my hair definitely looks sparse. It will probably get worse over time. I’ve heard about scalp tattooing, but I honestly don’t know whether I should do that or just have hair transplantation on my crown. Has anyone had hair transplantation only on the crown? What are the side effects? How painful is it, and is it safe? I have many questions about this.