You are still thinking 'couple' and 'relationship', and there is none.
I know you expected to hear exactly what you've heard. That she is a user, and you fell for it to the tune of probably thousands of dollars. She's cheated on you more times to count, and keeps you dangling on the end of a string- just in case she wants something from you.
For heaven's sake, her mother owes you money now??
I don't know why you are so naïve, and blind to what is happening to you. You ignore all the obvious signs, and justify her very bad behaviour, and you're continuously looking to justify the smallest detail, and explain away her behaviour.
Instead of concentrating on all the negativity and emotional abuse she throws your way, why not think instead of the positive qualities you obviously possess, that you can bestow upon another woman, who would appreciate and cherish you back. Love isn't about taking, it's about giving.
You are gentle, kind and generous. You are a good catch!! You're romantic and sensitive to the needs of others, and you care enough to put their needs first. You give, far more than you receive. You are loyal, faithful, and true to your values.
Now turn the above paragraph around, and pretend that is what you are looking for in a woman. And, I'm sure if you really think about it, you can add more.
So, if you have what you have now, and you could have what you know you could- isn't it time to cut your losses and move on?