I know what you mean. That is terribly hurtful to experience. Try being a bit less tentative when you attempt to join a conversation. Instead is asking a question, try making a statement that is relevant. Don't worry too much if the statement might provoke disagreement. If it does, that will actually motivate people to talk to you. When you mainly ask questions, you're not really contributing to the flow of thought. People can even view that as interrupting the flow of thought. You don't have to be contrary and contradict people. But try to come up with an insight that others might not have thought of.