Talk to Dermatologist on Extreme Hair Fall

It's been a year since I've been facing extreme Hair Fall. Due to my job timings, I was unable to wash my hair during day time so I used to take shower early morning and dry my hair by standing close to the inverter ac. The hot air from the inverter has damaged my hair roots to the point that if I touch my hair it comes out in my hand. Previously, I experienced the same a few years ago when I used to straighten up my hair using an electric straightener. The dermatologist in Fatima Memorial Hospital prescribed me to use Revivogen hair serum. It was the best thing I just say. But now it's not available in Pakistan. Could you please recommend me any hair serum/ medication which can make the roots of my hair strong? The roots are damaged.