John, what does your attorney say about this? You are consulting an attorney, right? If you're not, you should be.
I've looked at the General Terms of Probation for a few states, and all of them mention periodic drug testing as a condition of probation. Refuse or miss a test, and back to the pokey you go.
DON'T forget to visit your probation officer, and for the love of Mike, get a lawyer. This DOES sound excessive to my untrained self, but may well be the legal SOP where you are.

