Trying to find a new job.

So I have been trying to find a new job, and I got one. My new job didnt tell me I needed a drug test until today, 2 days before my start date. I have already left my old job (my two weeks just was up). I have bad anxiety and sometimes smoke weed for relief with that as I almost got addicted to prescribed drugs before. I'm scared I wont pass my drug test and I feel like it's not fair not to tell me about a drug test until 2 days before I start, what should I do