The thing is they don't know your personality and you can be pretty laid-back Or for many not enough active. They begin to misunderstand that you don't know any thing about the world. This misunderstanding can only be solved gradually which obviously needed your active part. You can always observe of what is happen in the family as an observer l, this can make you understand their habits and their way of thinking. You can than little by little (if you want to) mix in their life, like creating your dependency, you can also give your opinions then, but like suggestion in very gradual manner. When the people around you get used to you the misunderstanding will automatically be destroyed. Your habit to always be on internet create an interpretation that you are outside of the family. Try reduce your time on internet, Start making casual jokes.
Any relationship takes time and effort to maintain. This also applies to the people in your own house, to people who you see everyday. Relationship with family is not an unconditional one that will understand and support everytime. Like with friends, the relationship can grow distant overtime. As an introvert too, I am trying to cope too. Sometimes I feel like they don't understand me, sometimes also i realized that I didn't understand them until they explained it eventually. People are all made differently. What is normal to you, can be different from them. A generational gap is also huge, imagine living 20 years ago and forums like these are not part of life. And remember, people can not read minds. They cannot immediately know what you feel or think, vice versa.
Ugh i hate it too... Not in a way like you...but even if I say that neck or head or anything hurts it isn't taken seriously and when something hurts for them, they entire house has to serve themmm ughhh....