Problem with my thin asian hair! please help!?

I have thin, dark brown asian hair. I moved to US 2 yrs ago and had to change my shampoo, I've switched shampoos every now and then, and always use warm water for my hair, coz I can't bear the cold weather. I get dandruffs every winter and also itchy scalp. I try to shampoo everyother day now, when I lived in asia I used to wash it everyday with shampoo and it was fine.I notice now that my hair is falling more than usual and I'm afraid that I might bet bald! My hair line has a wider space than before, any suggetions to thicken my hair, and to get back the softness nad sheen it has before?