You did a nice thing in trying to help her get a start in her sobriety. You are not an idiot, just bamboozled by an active addict and I think we've all gone through that once or twice.
Perhaps her perspective of seeing how she could be living if she gave it up, will help her this round in jail.
I don't think any time was wasted, that you spent showing her love. I'm just glad you didn't get hurt worse.
Hugs