Ok. Your relationship with her will never be the way it was. NEVER.
This woman is a vampire and she is feeding on your life force. Do not call her, email her, go to her apt, or talk to her if you see her in public. Drastic? Maybe...but clean cuts heal fast and leave the smallest scars.
You are starting a new phase in your life and it will be scary. It's a tough time to give up a familiar relationship but there must be someone else from your past that won't take your money, time and energy.
Question: Is this woman a... bed friend? I don't need to know but it would help explain the relationship.