weight GAIN

im 18m, 6"2 and 9 stone

i cant gain weight, and trust me, i eat LOADS.
recently, iv been attending a gym for the past 3months 3 times a week+, and I have noticed a difference in my body size, im thinking about getting some weight gain supplements for my diet, any comments/suggestions?
also, my body is growing more hair than anyone else i know, which is kinda weird... this is just a natural heating system yes?

im not fussy about my appearance, Iv got what Iv got and im not 1 to complain, but I might aswell see what others have to say!

thanks.