Hi, I'd like to help you with your question.
It sounds like your girlfriend decided to leave on her own. If she had an issue with you, she would have brought it up. But she just left, which means there was something about herself that caused her to leave. No one just gets up and leaves if there are problems in a relationship that they are invested in unless there is something going on with them.
Because she left without explaining why, she left you with nothing but questions. And because you are experiencing a blow to your self esteem from the ending of the relationship, you are putting the reasons for her leaving on yourself. But you do not know that is why she left. There are no signs that it was because of you or even because of the relationship.
The best way to address this is to take a look at your own self esteem. What makes you take a situation like this and turn it on yourself? Finding out why you do this will help you see the ending of the relationship as something she chose to do and not something about you.
You may also want to consider counseling. A relationship that had trust that just ends causes a great loss. You need time to mourn and you need support. And you need help to learn how to trust again.Talk to your doctor about a referral. Or search on line at http://therapists.psychologytoday.com/rms/.
I think the list of your good attributes is a great idea. You were in a long term relationship so that means you can be in another one again. Focusing on your own good traits will help you see that you can recover from this and begin a new relationship. One good attribute you have is reaching out when you need help. That is a great strength and a sign of good mental health.
I hope this has helped you,