Too skinny?

Hi everyone,

So I just wanted to ask if I'm really too skinny. I'm 15 y/o, 1m74 and I weigh 52kg. Everyone calls me out for my weight. Whenever I eat, I either get comments about how I dont eat enough ("and thats why your skinny") or how I eat too much ("just to impress us?" or "I wish I could eat that much and be that skinny"). Its gotten to the point where I don't even want to eat in front of others anymore.

Also I'm seriously scared whenever I have p.e. because we have to wear shorts.

I seriously don't know what to do.

So here's my questions:

Am I too skinny?

What do I say to others when they call me out?

(I'm not fishing for "compliments" smh.)