Hi, I'm a recovering addict and I also post here at the Nar-Anon forums. My mother is the addict in my life, and it was so important for me to learn that when it comes to her addiction:
I didn't cause it, I can't control it, and I can't cure it. I get a lot of help at the Nar-Anon forums here.
You may want to come down to the Nar-Anon forums. There are some great posts at the top that address your questions. Nar-Anon is for family members (includes bf/gf) of an addict.
http://www.soberrecovery.com/forums/nar-anon/