How can i gain weight? Im so depressed with this struggle?

Im 27 and im 5'6 and 130 pounds.I am so bony! People always pick on my size calling me bony, little, asking me do i eat? Its embring because i want to be at least 150 pounds!I dont even look 130 i look like im 100 pounds! Some people think im on drugs. Im not at all!!! I eat but i dont know if im eating the right foods? Can someone please give me some tips because us little people have weight issues too.