Not at all an IPS solution but can I just say that a lot of booking websites identify users who have been repetitively looking at a specific flight and increase price of the flight for that user. Given your situation... WELL worth jumping onto a new PC and double checking the flight prices. — Jesse 2 mins ago

I expect this issue may now be moot. I don't see any of the answers @Tinkeringbell may have been referring to, but anyone who would make comments like that has no business in giving social advice. People stage interventions for their loved ones all the time, though I'm not certain this would be one of those situations. You might consider first seeking a therapist yourself and telling him/her what's going on. You could then discuss whether it would be fruitful to invite your girlfriend to attend and participate in those sessions. — David Reed 1 min ago