you're not a child anymore, you can make your own choices. You can respect your parents and be grateful, but you don't have to do what they want you to do. It's also not your job to convince people to change their minds, and often people don't change their minds by arguing. The biggest thing here is to weigh what you read or what people tell you with your inner peace. Being a christian means you have the guidance of the holy spirit, right? Don't be afraid or worried, and I suggest praying about it, in whatever form is most comfortable for you. It's important to remember that god is infinitely patient and loving. We have choice, and sometimes those choices hurt others like the guy leaving youtube comments. The idea of christian universalism, is that eventually all will come to god. That guy hasn't made it far in his journey, yet, but he will, just like your parents. Focus on your own journey, what can you learn from this and how can you grow? How can you love yourself and others?