I have a urinalysis test in 12 weeks help

Some context, starting a new job in the coming months, and the employer requires a urinalysis test, the test is in 12 weeks and 4 days to be exact. I am a heavy cannabis smoker and have been for the past year round about, I’m 6 foot, about 190 lbs, I know it’s a while away and I’m just stressing about if I’m gonna be able to piss clean by then, any help or reassurance please, or am I cooked?