How Safe Is Using Minoxidil For Thinning Of Scalp Hair?

Respected Sir,I am a Yemeni Guy, having hair and scalp problems. Here, I would like to give a short story of how I got such problems. Last year was my last year of doing master's degree in Hyderabad, India. In Jen, 2013, I noticed my hair started thinning on my scalp and I decided to visit a dermatologist. I visit a doctor there in Hyderabad. he examined my hair. After examination he told me you have to do Advance hair rejuvenation and told me you have to use minoxidil in addition to having some vitamins. There in his clinic, I did advanced hair rejuvenation. It was one session a month for six months with constant using a minoxidil plus Hiargain vitamins. After six months, I experienced no hair regrowth and some black areas around my eyes. So, I decided to stop using minoxidil gradually. In July, 2013, I stopped using minoxidil. After that, my scalp started secreting a lot of oil with white solid substances coming out of my scalp especially when I get exposed to sun rays. This causes my scalp getting dry and flaking, irritating too much. In addition, my hair is degraded, falling faster and converted to small baby hair. I lost a lot of my hair and I still have the same problem till now.I would be grateful if you could give me a proper treatment and advice .Regards,Mr. Waleed.