As an update:

My heart nearly dropped this morning. I received a phone call saying the company wants to extend an offer to me. I felt a little sick because this past monday and tuesday I got high because I thought I hadn't gotten the job.

The good news is I don't start until January 10, and they only need me to take a drug test before then. I have until January 3 to get clean. I think that should be enough time, but I will definitely home test before then.