I’m so sorry to hear your family is being unsupportive of you being a vegetarian! My family used to be the same way, until they saw how much it meant to me.
Try talking with them about it and let them know how much being a vegetarian means to you and that it hurts your feelings when they mock it. They might not even be aware! You can also try showing them our Glass Walls video to show them WHY you’re a vegetarian. http://www.peta2.com/videos/glass-walls/