I agree with what everyone is saying, yes she should of talk to you about any misgivings but she chose a second route.
Trust is the easiest thing to gain but when its lost its hard to get back. I'm gonna speak to you from experience, at the end of the day it doesn't matter what everyone else says or feel about the situation it only matters what you feel.
Yes she did hurt you but are you ready to give up on the relationship, call it quits for GOOD? Many people say what they would have done in a situation similar to yours but you never really know what you would do until you're the one in that situation. Yes its gonna be hard for her to gain your trust back, but you should speak to her and let her know how you trully feels now she has broken the trust that both of you shared. Let her know that the relationship is not gonna be easy now and as a result of what she did your gonna get jealous and think the worst before you think of the good, and that you'll always be wondering what she's doing when she is not with you. At this stage in the relationship communication plays a key factor if this is gonna work inspite of the situation at hand.
At the end of the day the only thing that matters is how you really feel!! Do you want to give it another shot because you love her? After a break up do you know what torments us the most, IF WE FAIL TO TRY!! When the relationship is over you want to think back on it and say to yourself you tried all you could, you gave it your best (being 100%) and it didn't work out. You don't wanna ever think back and say WHAT IF I gave it another shot!
P.S Inspite of everyone thoughts do you wanna try again?