Hair Growth

I know this isn’t the right place to ask these questions, since it’s about Manga/hwa/hua and stuff, but what can make your thin hair thicker and fuller? My hair is falling and it’s becoming even more thinner. I’ve used rosemary oil but I fell like it doesn’t help or I’m not applying it right. I have wavy hair but recently my curls are disappearing, anything I can do or use to make it wavy/curly again??
+also someone I know has frizzy hair and hair loss anything good for that??