Help with my Probation officer?

I got arrested last October, The officer gave me tickets for Illegal transportation of alcohol, possesion of drug paraphanilia, possesion of 2.5 to 10 grams of weed, improper lane usage, I ended up getting everything dropped but the DUI for marijuana I had to get an alcohol evaluation and got 12 months couurt supervised probation and have to attend cles, On my deal it said I also could not use alcohol or drugs during my supervision I had to provide a clean drop to even get the deal my problem is I relapsed and my probation officer wants me to come in this Friday it is my first time meeting her or seeing her I know that if she drops me it will be dirty what can I do to avoid getting dropped if I give a dirty drop all the charges go back into affect and I still have to pay the money for the deal I have qquit smoking now so I can hopefully get through this I dont want to loose my license for 3 years I know it was stupid to smoke again but please help.