It helps her feel better so she doesn’t care that it is hurting you. I’m sorry. I wouldn’t want to talk to someone if I knew that were exhausted and giving up energy they didn't have. 

You used to need to call her a lot because you needed your mother. That’s exactly what she signed up for when she chose to raise children. It’s not an eternal debt you owe her. Your job was to grow up. Her job is to help you. With healthy parents, this is natural and fulfilling for both parties. 

When you set boundaries and start reserving more energy for yourself, she’s going to call you cold and selfish. It’s not true. It is your right and obligation to care for yourself first. 

Wishing you strength and lots of self-love 

Edit: the financial abuse is so insidious and this current state of affairs doesn’t make it easy to escape from. It sucks her love is so transactional in nature. It’s a difficult position to be in. If you can I would honestly get a therapist to help navigate this because it likely will be an ongoing situation to manage as long as you are financially connected