I can understand your reticence in not wanting to disclose who supplied your drugs.
However, a part of me thinks it is admirable of services to want to uncover who may be dealing to potentially (particularly) vulnerable people. Although another part of me also agrees with you that this information may not be as important as ensuring your wellbeing which, one would hope, would be their top priority.
Below is a link to a UK Drugs Support Service with a helpline. Perhaps if you contact them they may be able to advise you on how best to manage the professionals around you so that they stop focussing on wanting information about your dealer and instead begin to work positively on the bigger issue of helping you.
