Quit after 6 years of smoking both weed and cigarettes. Joining boxing was what helped me to stop, so BJJ can definitely be your key to quitting.
The trick is to do something especially grueling like hard running, sparring, or rolling. Eventually your body and brain will begin to rewire itself to want the endorphin rush from hard exercise rather than nicotine. As your lungs begin to heal themselves, they'll just start to reject the tar and smoke associated with lighting up.
I remember some days after sparring I'd feel like smoking a cigarette but couldn't physically bring myself to inhale. And with all the fucking disgusting shit I was inhaling (all the tar, bongs, blunts, joints, cigarettes one after the other, resin) I thought the damage I had done to my lungs was irreversible but it wasn't. So with that said good luck. I know it's cliche and everyone says it, but it really is one of the best things you'll ever do for yourself.