Would this be illegal?

[A]

I am 19 years old and a college freshman, and my parents are coercing me into giving them my Facebook password and then looking through my messages. Every time I change the password, they coerce me into telling them the new password by threatening to transfer me to another college 12 hours from home if I don't. Just tonight, they called me to scream at me over a recent exchange with my boyfriend (which woke my sleeping roommate). I have repeatedly asked nicely to have privacy with my Facebook messages, but they still insist on having access to my Facebook. Since I am a legal adult, is it illegal of them to force me to give out my password? Why or why not?
Inda Cloud, I see two problems with your idea:

1) if I make a second account, how will I transfer all my photos and friends to make it look identical to the real account?

2) if I message people on this second account, my parents will hack my original account and notice that there are no new message exchanges. They will not see my conversations with them or my boyfriend (on the second account) and then hack my second account. Therefore, the second account will waste my time.

How do I work around those two issues?