My first suggestion would be to contact your detox provider or your own general practitioner. There are other causes of headaches than those after anaesthesia or detox. I have had several detox patients who have complained of generalised headache with no localising signs or symptoms. I believe that a common cause of this is dehydration as the detox procedure itself seems to precipitate diarrhoea and vomitting which can be partly relieved with medications.
Some patients have problems to drink enough fluids while thay are in detox under sedation.
I usually recommend a minimum of 3-4 litres per day of an alkaline electrolyte replacement. In Hong Kong we have OTC powdered Pocari in sachets to be made up with water by the litre. This is more palatable and much cheaper than the oral replacement fluids available in our hospital pharmacy. I usually recommend that patients continue to drink 3 litres of Pocari for 3-4 days after discharge. If the headaches continue it would be reasonable to try a non opiate analgesic such as paracetamol or ibuprofen.