Hair, scalp

Lately my hair has been falling out so easily and so randomly (not in clumps and not patches) My hair was healthy all of last year except for like november and december, i’ve dyed it twice in 2017 and that’s probably the least amount in a year ive dyed my hair. my scalp has been itchy, and when i itch my scalp it’s very sensitive and hurts a little bit. the right side of my hair is 5-6” shorter then the left side of my hair and i do have to put my hair up every day for work but i hardly ever straighten it. any idea on what i can do to fix this. or should i go to a doctor