I've gone through my ex's text messages on two occasions. I was wrong for doing so. She was wrong for not voicing her opinions of her ex talking to her and keeping me in the dark about it. Me and her were both wrong and if there isn't any trust in a relationship, it's destined for doom anyway. If you can't trust her, you shouldn't be with her. She isn't something you have to keep your eyes on at all times.
So you guys broke up. Yeah, it's pretty typical to go through all the old things and sulk in your sadness. Eventually she'll get sick of it and go out and live life or maybe possibly delete your photos to "help her" move on. Your focus shouldn't be on getting her back, it should be on how to live life without her in it. So logging onto her computer and invading her privacy isn't helping you. It's hurting you and your progress and your growth.
We all break up, and we all find ways to deal. I never found this to be very helpful. I would advise not to and start concentrating on other things, even if she is all you think about. You have to push through this somehow.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.