I'm a female so im not sure if this method works for you, but i have case of severe hair loss and managed to grow it back.

1.Go for scalp treatment every month or 2 month, it is EXPENSIVE but i personally vouch for this one and please go to a reputable hair salon.

2. Buy viviscal hair growth pill, u can find it at lelong but sometime it can be sold out so u need to check it all the time. Unless you have relative living in the US to buy for you through amazon. My advice is to buy one box first to check the compability of the product with you.

3.Live a healthy lifestyle and try to eat more things that are good for you skin and hair.

4. Buy non sulfate/paraben shampoo and try to avoid putting hairspray/gel. Go for natural if possible, there's a lot of organic/natural hair product. Sometimes you can even make it at home yourself.