I am 26 years old very skinny, height is 180 cm and I weigh only 52kgs, working in a corporate sector, so feeling myself shame for being skinny.

I am pure vege, I used to take 500ml milk before I go to bed but no success.. *** suggest me

Being a vegetarian will not make you gain weight. It's only when you start eating junk food or greasy, fried food that you will gain weight. There is no reason to beel shame or embarrassment being skinny as most people today are overweight and can't lose the weight and only wish they were slim like you. Don't force yourself to eat junk food to get fat. Be yourself and be proud that you are slim and fit.

You are given the body you are given and you shouldn't be ashamed of it.

Just continue to eat a balanced and healthy diet and get regular exercise. How your body shapes itself when properly nourished and exercised is out of your control-but you will be healthy and fit and that's all that truly matters.