Most Helpful Girl
Ok, you need to stop beating yourself up for her behavior. Her cheating is NOT a reflection of you. She has shown you the kind of person SHE is. Is that what you want in your life?
The truth is, it is not important WHY she did it. It doesn't matter. This is an example of the low level of respect she gives partner, and you have higher standards than that.
Don't hate yourself because she cheated. You are not to blame. You did not deserve it.
If anyone here is not good enough for someone else it would be her. She's the one who doesn't deserve your love. Give yourself time to heal from this heartbreak. Not all women are disrespectful in this way. Focus your sights on finding a good, true girl who will treat you with the same love & respect you give her. You'll get past this, I promise you.
Most Helpful Guy
Do you think it will help you get over it and recover? Will it help you bring closure to the relationship or will you only be opening an old wound? No one besides you can answer this because your the one who knows yourself the best, whatever you think brings the most amount of closure and relief possible is the best way. Either that be trying to find out why or entirely blocking her from your life, or anything in between, its up to you. Don't blame yourself though, its not you, a cheater is a self entitled brat who need everything for themselves, if they can't get enough out of you they look for the next thrill.