Waste of time
My recommendation would be to find a way to move out of your parents house.
And for the record, you can drink, even if not of legal age, in your parent's house. You will not get a minor in possession charge. Now if you are not in your parent or legal guardian's house, then you have a problem. But if your parent or legal guardian says you can't, you can't. Period. Welcome to America. We can do a lot of otherwise illegal things in your own home. We call it freedom.
Next, the argument for not drinking before 21 is not because it's illegal. It's because your brain hasn't finished being formed fully and you increase the chances of addiction as your brain finishes it's formation. Now, if you are 19 or 20, the odds of becoming addicted are much less than if you are, say.... 14. Waiting won't hurt anything. Learn to have fun without alcohol and I guarantee you that you will have much more fun WITH alcohol later in life. Just a personal experience I am passing along to you, as a drinker.
Next, the word of wisdom was a recommendation until the late 1800's, not a mandate (it was given as a revelation February 27, 1833 after the prophet had a problem with tobacco use at meetings). Joseph Smith was long dead before the church made it a requirement to go to the temple or even took it very seriously. Joe Smith had a liquor license while Mayor of Nauvoo! Many famous mormons from the early days, even my relatives (Almon Babbitt is in the D&C and was the Treasurer for the Territory of Utah), enjoyed the occasional nip. The revelation about the ban on drinking came after some of the sacramental wine (yes, they originally used wine for the sacrament like all the other religions) was poisoned. They caught it before anyone ingested the poisoned wine, but shortly thereafter, Joe had a revelation about the word of wisdom. Even the word of wisdoms says you can use wine BUT you have to make it yourself! (so no one can poison it). Don't believe me? Look it up. Mormons have a long proud history of timely revelations. For that matter, you can even look up why alcohol (wine) was originally used in the sacrement. It has a good history. But the reason Jesus turned water into wine was not because he was a party animal (although I have no doubt he could be a lot of fun). It was because you just don't drink city water in those times. It would kill you. Wine (alcohol) killed all the little nasty's that killed the drinker. Beer made city life possible!
Joseph Smith drank alcohol for pleasure on a number of occassions as documented in the History of the Church.
On Wednesday May 3, 1843, Joseph "... drank a glass of wine with Sister Jenetta Richards, made by her mother in England ..."
On the night that Joseph was murdered he drank again. The LDS Church records describe in detail that, "The gaurd immediately sent for a bottle of wine, pipes, and two small papers of tobacco; and one of the gaurds brought them into the jail .... Dr. Richards uncorked the bottle, and presented a glass to Joseph [Smith], who tasted, as also Brother Tylor ...." (History of the Church, vol. 6, pg. 616)
Some may argue that this was for sacrament so I will address this argument before it starts with John Taylor's statement. "Sometime after dinner we sent for some wine. It has been reported that this was taken as a sacrament. It was no such thing our spirits were generally dull and heavy, and it was sent to revive us" (History of the Church, vol. 7, pg. 101)
In addition, Joseph Smith had a liquor license to distribute alcohol from his home. Take a look at History of the Church, vol. 6, pg. 111, "Section 1 - Be it ordained by the City Council of Nauvoo, that the Mayor [Joseph Smith] of the city is hereby authorized to sell or give spirits of any quantity as he in his wisdom shall judge to be for the health and comfort, or convenience of such travelers or other persons as shall visit his house from time to time."
At any rate, I would really suggest you find another living situation. Being 'right' will be small solace for having to live with people that would choose dogma over blood. If your parent's don't love you despite your faults (in their eyes), they have missed the message of mormonism entirely. You're better off elsewhere. Love them from a distance, but go on with your life.
I'll raise my glass to you tonight.....