Jeff, what she may or may not be thinking has no relevance here. No matter what the cause, the fact is she's stringing you along. Now, are you going to be her puppet or are you going to place some boundaries for how you will or will not be treated.
My advice is to tell her that unless she's willing to commit, you will be moving forward without her in your life.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.