As mentioned already, communication is key. Talk to your girlfriend and ask her what you think, sure she'll get mad at first, but if you guys have been together for a while and are also best friends she'll understand. If she is using you for your money then call it quits because that's not healthy and your relationship wouldn't be authentic as before, but it also takes time. If she realizes her mistakes and wants to start over with you, try it, if you really want to. If she changes, great, if not, then sorry. It's better to move on then to stay with someone that'll take advantage of you. Good luck, do what makes you happy.