"What other people think of me is none of my business" It's what you think of you that is important.
Do you enjoy what you are doing? Of course you do. Have you considered they may be envious that you have something to be passionate about that doesn't involve clothes, boys, partying and drinking (I'm assuming here as I have an 18 year old daughter (God I'm old

...but I don't feel it...often

)) Do they have people on the other side of the planet (a planet that you probably know far more about than they do and understand how fragile it is) that they can talk about their passion with? I don't think so.
It's called tall poppy syndrome Sonia. If you dare to stand out above the crowd there are people who are always ready to try to cut them down. Even you friends. It's fear, based on insecurity. We, everyone, get to face these challenges. It's how you respond to them that can often determine the sort of person you will become. Strong, confident and not afraid of a challenge, or stuck doing the same thing day in day out.
Friends accept their friends, without judgement. My mates think I'm a raving loony, but in a loving way