How would you respond to this sort of person?

I have a girl friend who like… never stops texting me her issues every single day. This is just from today over a span of 2 hours that I didn’t respond. She is in her 30s and works as a librarian but still lives with her parents and complains about them constantly. Has major anxiety about everything and I think uses me as a dumping ground. She never asks me how I am or seem interested in me. I know she has severe anxiety/mental health issues but I can’t constantly respond to her 24/7.