Lots a good replies. Everyone's advice I read seems to come from personal experience, and since no two situations are the same, I'll share mine to see if you can take something from it.
I moved out of my parents house when I was 17. Before i had ever even tried pot (I was completely anti-smoking), then they had me drug tested twice, which just turned me to rebel more. HIND-SIGHT IS 20/20!!!. Now that its too late, I wish I had done more to get closer to my family when I had the best chance, no matter what I wanted personally/selfishly, wish I'd put getting to know them better first, instead of distancing myself. You only have a short time with them, make the most of it. Fuck smoking pot, its not gonna do anything for you. The best thing i could recommend for you to do for yourself, would be to do the most you can for your family members. Be their son/brother, not just a tennant in their house. That will leave you more fulfilled then pot ever can.
I remember the days of being an invincible teen. If I knew then what i know now.......Once I had enough (really just gave up and took easy way out) i moved out and graduated highschool early. Working and paying for school on my own was ok, but not what I thought it was gonna be. I tried to fill the hole left from leaving on bad terms, with pot, but nothing replaces family. As great as pot is, its not a friend, or a family member.
In short, things are not what they seem. You are young, and passionate. Think things through, dont act with your head, follow ur heart--ur ego (image of self) can get you in trouble. You know the right thing. The hard part is not ignoring what your heart is telling you to be the right thing. The right thing, is more often the hard thing to do. You could take the easy way out, burn bridges along the way, and you'll even tell yourself ur fine/happy, but eventually you will realize that even maryjane and being busy cant fill the hole, & that family can make you whole. And also, get a job, think about the future. Take advantage of the money saving opportunity of living off the parents. When I moved out i had $7grand saved up from summer jobs, but now its impossible to save anything. Its never too soon or too late to save $. Even minimum wage is better than jobless while milking the parents. Have some pride and earn something for yourself. Ur 19, not a kid, and soon not even a teen, take off the Pull-ups and act like an independent man, and that's what u'll become. What would u do if ur parents kicked u to the curb today (I would if i were them, time to see if u sink or swim)? Without a job, u wont survive long. Just telling what I thought u needed to hear. Welcome to the real world.