why should i respect my parents if they dont respect me?
As a parent of 2 teenagers I can say that parental "respect" is a concept that often gets intermingled with trust, hopes, desires, expectations, and a lot of other things including a deep understanding of each other from years of living together. Another thing is the fact that your parents probably made many (most?) of the same mistakes that you (will/have) do, and they would want nothing more than to be able to protect you from damaging yourself unnecessarily. Kids are just kids, and adults are (supposedly) mature, but during that decade from about the mid-teens to mid-20s, when they are struggling to find their place as "real people" in "the real world" those levels of maturity and immaturity are constantly in flux and not often mixed homogeneously.
Actual respect is something that must be earned continuously and can be broken quickly. Children owe their parents a lot. Think about it. You are obligated to repay your debts to your parents to your own children.
As my original martial arts master taught: "It is more important to know your weaknesses than it is to know your strengths."
