You sound like a very caring person, which opens you up for being taken advantage of. You need to learn to say no and mean it. If you are seeing a therapist, ask them to help you with learning to say no. You need to quit listening to the stories. They are sucking you in with them. Tell them you are out of money and not to come back.

Thank you for trying to be charitable but when it starts to hurt you, you've done too much.