How to get through to brainwashed parents?

Here's the details before I continue to whats going on. I'm 19 living with my parents while I go to college to save money. I smoke regularly almost every day. My parents think I smoke because I'm addicted but I smoke because I have anxiety and have trouble being creative and weed helps plus I tend to have anti-social tendencies (not good if you are in college). They think that my problems can be solved with with anti-depressants and adderal, I have ADD as well.

So here's the story I had an oral drug test coming up for a job and they caught me smoking about 5 days before drug test. They now are trying to force me into signing a legal contract saying that I won't do drugs while living in their home and they go on and on about how marijuana ruined my Uncles life. My uncle was an alcoholic and crack head by the time he was 12 and for some reason they think all of his problems were caused by weed. Well anyways they are trying to get me to sign this contract and if I don't they are threatening to take away my insurance, kick me out and possibly take away my funding for college. I have been fighting back I have been showing them clips from the Union along with government funded science journals about how weed is the best thing since canned beans. They just respond with how my brain is being controlled by addiction and they proceed to show me videos of Dr. Drew about how bad weed. Dr. Drew as you all probably know is payed quite handsomely by Big Pharm to prescribe anti-depressants often to people he sends to rehab for marijuana addiction. When I mention this to them they give me the same fucking retarded response about how my brain is being rotted and controlled by weed.

Is their any way to still smoke and convince them that it is ok. This is my last resort I feel that I have tried everything. I offered to get family counseling but I found in my parents history them looking for counselors that are anti-marijuana so I know I am not going to get a fair hearing from the counselor. So is their anyway I can salvage my relationship with my parents without bowing down to their demands or is my only option to leave and never look back if I still want to smoke.

 

I think I accidentally posted this three times. Not sure how. I mentioned my Uncle before but I thought it fit here too.