get out the dremel and drill a tiny hole into a tooth you don't use much. Eat lots of candy, especially before going to sleep. When it hurts real bad go to the dentist. When he wants to do a root canal tell him you can't afford all that fancy stuff, just pull it. Then go home and smoke some cigarettes. The next day you will have a dry socket that hurts like hell. Call your dentist. He will call in a script for some hydro. Cold water extract the whole bottle and slug it down.
Less painfull than going into the Mega-Low-Mart and much more effective.
Even better: check the obituaries. Day after the funeral for some really old fart, go to the door dressed in a suit. Tell them you are from the State Dept. of Health, and you are supposed to pick up all the deceased's medicine for proper inventory and disposal.
Get a buddy to help you, dress up in suits and pretend to be mormon missionaries going door to door. When an old woman answers, start weaving around like you're dizzy. The other guys keeps you upright. Say you are suddenly feeling poorly, you need to use the bathroom right away. Once in the john, go through the medicine cabinet.
At least you stand a chance of getting some real narcotics.