Hi, lostinlove, welcome to PsychCentral (PC). Instead of thinking with your emotions, do some thinking with common sense and take your feeling thoughts to their logical conclusions? If she can be "stolen" from you, how real has the relationship been in the last six years? Do you want to continue to build a life with someone who can/could be stolen?

Are you not able to visit her at all, help encourage her while she's in rehab? It doesn't sound like an easy process if she is staying longer; I don't think she'll be thinking about making new love connections working/hurting so bad in order to get back to you and her good life?