Your height is average,  so no need to bother. You are blessed with a baby face that is a bonus which suits your  height. I suggest to practice yoga and surya namaskar every day  for proper metabolic process.  Also eat food on regular intervals to absorb maximum nutrients  for gain.Include protein rich high calorie food like eggs chicken fish paneer  curd, soya as tofu and whole pulses like moong Chana choli chole rajma etc