There is nothing wrong with you that abusers are attracted to you. We can't change the past, but next time a someone you are unsure about approaches you, show them that you are not someone to be messed with. This can be done in a civil and friendly manner, such as setting firm boundaries and not giving in.

For example, you can tell someone you cannot offer a last minute help.
And if that person texts you with a last minute request, don't respond. Ignore it.
Respond after the need has passed and say, "I'm sorry for the late reply. As I have mentioned before, I cannot offer a last minute help."

If you respond to her text right away, you may end up having her texting you into making an exception;
or even if you don't give in , you would end up in a dialogue with this person for something you claimed to be non-negotiable.

Even if you don't give in, you are showing the person that you are willing to open the door to a manipulative conversation.

Don't open the door. I remind myself this all the time.

Abusers, just like anyone else, are attracted to your good qualities. But you can still take measures to guard these good qualities from their exploitation.