How to make them understand the difference between functional coping and getting "high"? They see you each day and know that you are going through something enormous, they try to be understanding but at a point really just hope you'll cope and it'll all be okay. They cannot understand it as we do because one needs to live this Hell prior to realizing that the meds are the most basic level of care, not a recreational wonderland.
Like yourself I am extremely angry that those of us with real injury/condition related pain are lumped in with drug addicts. The Doctor's are more concerned with answering to regulators than with treating their patients. There is an air of fear and distrust that has come to be associated with anyone who walks into a Doctor's office and says they are in pain constantly.
My current Doctor informed me at my worst point of injury pain that he had "no interest in treating your pain, if you think I'm going to give you Narcotics then leave." I was suicidal with actual physical pain and the emotional side of things was not helping. I didn't give into his negative attitude, I jumped through all his hoops (tests, MRI, CT etc) and he gave me basic pain meds. It was a very hard won basic level of care. I still struggle with even being able to deal with him but there is no one else. The 3 Doctor's before him just said "NO".
The point here being that this is a worldwide crisis. The societal attitude has permiated from our friends/families to our treating physicians. If they were to walk a mile in our shoes they'd hope that we'd show them the mercy we have not been shown.
It's a horrible feeling trying to not only deal with the reality of each day but the constant over-shadow of having to prove yourself constantly.