Unfortunally you are correct, it may be best for you to leave the small group and find another where you can grow and learn more about God. The leader of the group should have put a stop to it long time ago, but maybe has failed tosee your point of view. Maybe he dont know how you feel? Have you told the leader whats going on, and how you are being misstreated? Maybe you should start there, not comfrntational but with more of an imfomational kind of additude. But I would still start looking for a place that you would be respected and be treated like and adult and with the respect you deserve.
But before you do anything please make sure your pray to Jesus and don't anything till you get an answer from him. Or you may be moving ahead of his timming.
May our Lord Jesus keep and bless you.