Seems like you have a strong head on your shoulders. This decision is yours and yours only to make. yes family will eventually come around and will always be there. If you can afford everything on your own without having to sacrifice anything than you know what call to make. At almost 20 you are now an adult and the decision to get a motorcycle whether right or wrong in your parents eyes is your decision. Every man has to come out of their parents shadow and make their own calls. I guarantee you they do this out of love and not to hold you back. They love you so much that they don't even want to think about you getting hurt on a bike. So prioritize what is important to you and make the decision.