Hey There....my Name Is Arup..i Am Writing From Canada...ever Since

hey there....my name is Arup..i am writing from Canada...ever since i came from Bangladesh to canada i have lost a lot of hair on my scalp..like mostly on my middle portion....and i experienced hairfall within the first few days of my arrival into canada.....I was also diagnosed with psoarisis of scalpe within 1 year but my psoarisis is under control now....so my question is how fo i regain back my lost hair