Yeah, stop answering.
You don't have to answer to anyone about what you do in your free time. Specially not this one.
If you're not seeing other women(like most of us advised you to), at least act like it.
Every time you respond to her
texts at night she knows you're not doing anything better with your time. Get it? And she will perceive you as lower and lower value.
Just try this once, ok?
Next night she texts you, ignore it. Let the message hang there. I guarantee she will ask you about it. If not, do it 2nights in a row.
It will drive you mad and she WILL ask you. You casually say "I was on sort of a date" or something.
Pretty easy, right? Are you able to do this? It's a level 1 quest.