RTS0073;
Bad news, you cannot legally operate a CMV for upto (most likely) 3 years. If the carrier you drove for at the time of the failed random had a return to work policy, you may have been able to stay with that carrier for the "return to work" and "follow-up" testing period, following the direction of a Substance Abuse Professional (SAP). Sounds like you were terminated at the time of the positive test.
It will be very hard to find a carrier to drive for now that you have that positive test. This will last for a period of three (3) years. I would suggest staying out of trucking for this period - it will save you much frustration. The constant denial of positions would be brutal, and most likely, you will not find a carrier willing to: hire you; assist you with a return to work program; and pay for the return to work program.
The Carrier you were driving for should provide you with information on the consequences of a positive test. You should be referred to a Substance Abuse Professional for additional assistance.
I would suggest you read 49CFR (the green safety regs book) in Part 382.
Good Luck,
HotFr8Recruiter