What should I do any advice

I have been with my girlfriend for over 2 years now and recently she went on holiday.When she went away out of curiousity I decided to buy another girls used clothing as I am turned on by some of the smells .To cut long storys short she came back and found a parcel and demanded that I open it.Since then we texted that night after she left and she asked me a lot of questions I told her I was sorry and that I shouldn't have done it and that it will never happen again.Following that I waited about 48 hours and I called her we talked for a while and she seemed more calm but asked me more questions.Then I talked to her again that night on facebook which was a big mistake both times unfortunately I made the contact and things didn't go so well after a lot of questioning.She just kept saying I don't know,I don't know and said sort it out a few times.
Since then I haven't contacted her and about another 48 hours have passed is this definitely my best option?I had seen her on facebook today but resisted talking I waited in hope but to no avail,then no sooner than I left she left maybe she is even waiting for me to contact her too.Do I really have a chance even with no contact?
Many thanks if you can help me or at least talk to me Ben

Can you keep that promise to never do that again? If so, I suggest writing her a letter - not a facebook message or text - saying that you love her, that you know it was a stupid thing for you to do, you won't do it again, will she please give you another chance. You may have said it already, but having it all written down in the one place makes it easier for her to read and remember.

Then wait. She'll respond eventually. She hasn't blocked you on facebook, so she hasn't made up her mind yet on if she does or doesn't want to be with you still. Sending a letter is more personal then FB or a text, and it allows you to say everything you need/want to without interruptions or forgetting things.

Don't be embarrassed by what turns you on, but do know what you'll do to stop yourself from getting that from outside of your relationship. Perhaps she'll give you some of her own clothing next time she goes away. If she won't, you'll still have to keep that promise and you'll have to find some other way through.