I feel like i cant trust my girlfriend anymore?

If she in fact is lying, she will not own up to it. The problem is proving it. The pictures might insinuate that she's lying, but then again, they're only pictures and they don't really prove enough. But, you should know her better than anyone else! If you know for sure she's lying, then you need to move on. But if you decide to do so, you're going to have to be strong with yourself about it and stand strong on your feet. In other words, don't let her soften you up and then go back to her. Don't let your emotions control you, you must be able to control them. If you leave, do so and don't look back. Because if you do, then you'll be back to square one. Right back to the same crap and the same crappy feelings that you're feeling right now.