When i was young there was a girl in my class who was an only child, but we never knew that until years later. She was so friendly and very positive. A few years later, another only child entered our class and boy was she spoiled and not the most pleasant person to be around! Until she entered my class, i never even thought about an only child being different from me.
I cannot judge as i dont know what its like to be the parent of an only child or to be an only child.
As far as nasty comments people make, that i can relate to in a different area of my life.
So good luck and dont let those nasty comments get to you, just look where its coming from!