At this point, there is not much she can do but continue to harass you.  You have not committed any crime so there are no charges that she can press.  She willingly sent you the photos and videos.  I would suggest the first thing you do is change your phone number so she can not continue to text you.  If she continues to harass you, you can file for an order or protection or injunction against harassment.  This is a lesson learned, you really should not be engaging in this type of activity if you truly have a girlfriend.