Justlizzy, you and I have a lot in common - I too blamed the lowlife friends who set her up with oxy's, patches, you name it. They knew she had a problem but misery loves company. Hell, even one of my so called friends sold her percosets and KNEW it was for a high, not "back pain".
But in the end it is 100% her choice to be an addict or to be in recovery. Not her friends, not me, not the lowlifes. I think what's hard for you to see is that the toothless tweaking lowlifes your husband associates can and will be him someday if he doesn't get off the ride. He can't see it, but you do. All the more frustrating to realize that you can't stop it; only he can if he wants to. What you can do is decide how far you want to go on the ride before you'd like to get off.
I've chosen to stay with my A b/c she is in recovery, b/c she wants to be there and is working her program. She'll be out in about 30 days or so and we'll see if she stays as committed. That part is not up to me. All I know is that I will not go back to being the bitter, angry, joyless person with all the life sucked out of me that I was before.