Admission into the pretrial diversion program is up to the state attorneys office. They are the gate keepers of the program. You should have your attorney contact their office to see if they could refer you back into the program.
Typically the judge will allow you a free pass on the first drug test, however, diversion is run by the State Attorney's Office and is a privilege, not a right.
You just can't skate on thin ice. PTD was a big gift. You should consult an attorney to see if you can get back into the program. You cannot do it yourself.