Uncomfortable about asking for stronger pain medication. Will doc think I'm an addict?

Maybe not. Not every pain medication works well for every patient. Rather than asking for more pain medication, describe what is happening with the regimen you are on.
What do you think? If you are concerned about being an addict, you might want to consider attending a meeting of narcotics anonymous. Find a meeting at their web site: http://www.Na.Org/.