I don't think you are acting spoiled. It is your choice. Yes you are young, and it may be a struggle, but it is your decision. I went through a similar thing when I became vegetarian at the age of 14, and to be honest it is still an issue raised at times, so I would not wait until you are out of the home. My being car free raises issue all the time, not many people understand it.
I stuck to my guns and found good, close friends, who supported me, and this made it easier for me.
What ever you choose to do, do it knowing that you are doing what you want to do.