Being honest does not promise one a clearance. Lying, and being caught, just about guarantees a denial, but telling the truth does not guarantee one being granted. No one can say for sure until you get your SOR, but it certainly sounds as if your heavy drug use is the reason for denial. What you have described is all illegal, and is often the cause of denial.
Also, the timeline you have described to go through adjudication is very possible. My T5 investigation was successfully adjudicated in a much shorter time last year. (It wasn’t for a three letter and didn’t require a poly, so not apples to apples, but meant to show the timeline is possible.)