Severe Hair fall but no reason found yet

Hello Doc I have sever hairfall from last 2 years also treatment from best dermatologist in Bhopal but the reason of my hairfall still unknown. I have done almost 10 + test like blood, harmone, tyroid, keratine, vitamin D, PCOS and many others but everything is normal and good...Last year doc started minoxidile 5% but after 3 months when I stopped double the hairfall happen after that i tried various thing under supervision of dermatologist but nothing happen taken many multivitamin and other things but nothing happen...Now after depressed from my situation i again visited a very good dermatologist of my city and he prescribed minoxidile 2% again with some multivitamins and shampoo...I have so much fear to start it but ri8 now i have no option because everything gone vain in last year and my situation is very bad i'm almost bald...please genuinely help me feeling to sucide now after seeing all this.