Time to discharge them as your therapist and find a new one, because that is completely unacceptable for several reasons. Not only are they accusing you of using illegal drugs- which means that she has likely written things in your files that say you use drugs, which is a violation of ethics- but therapists are never supposed to use accusatory or hostile language or tone. Additionally, if they suspected that you were abusing drugs, they should have not only brought it up sooner, but phrased it in a more tactful- and PROFESSIONAL- manner. You can't trust anything they tell you anymore, because they failed to act when they had reasonable suspicion. You need to get your records, get their medical practitioner information, the rate they charge, compare it to what you pay, and if you have insurance, you need to make sure they billed for the correct amount of time and diagnostic codes. If anything like that has been changed, you need to report them- but make sure you follow procedure and have a new one willing to take you. If you live in America, I suggest contacting the American Psychological Association, and if they are a member, report them for the unprofessional behavior and anything else. If not, contact your state's licensing board and file with them.

“Y’know, Sarah, you would be a lot happier if you lay off the cocaine. Susie, I’ve been off the stuff for nearly three hours, and it’s been amazing, Stella!”