If she has trust issues, she probably has the "better to get, before got" way of thinking. She probably assumed that you too would hurt her and did what she has always done to prevent herself from hurting. Depression and other issues can also cause some bad choices in life. Perhaps she doesn't understand what it is like to have a committed and trustworthy partner. Face it, not many people have ever had it as part of their life, so it becomes "normal". Over the last few decades children have experienced that it is OK to throw away a relationship because it is too hard to work at it. Everyone wants instant gratification and is never happy with what they have. Have faith that you did nothing to cause her to be this way. Some people are never happy. They have no idea what they want and will spend most of their life looking for it! There is nothing you could have said or done or proven to her to change it. It is sad that this has happened to someone who sounds very kind, sincere and loving. Don't give up on yourself! I have been on both sides of this cycle. It SUCKS! You will need to start loving yourself again to find love to share with another! Hugs to you!