Hey Bobby. You did handle it very well. That is very similar to how things were with my STBX and I. She also is in school and very stressed out all the time.
During those times I'd get very similar behavior. I remember once she asked if I was going to take the kids to church. I said I was. Suddenly she jumped in the car and went along. I was dumfounded for a long time; confused.
I recall once that the MC told me that what the stbx did was going to happen either now or 10 years from now. It was a question of time in her opinion. That's not a bad thing is what I'm getting at. Sounds like she needs to have the space and you are giving it to her. Hard as that is, that is what you need to do EXACTLY. She is telling you this, and you seem to be doing it.
Hang in there. Things change all the time and you'll need to be fluid to handle the changes.
"Our lives begin to end the day we become silent about things that matter" MLK Put the glass down... "Yesterday I was clever so I wanted to change the world Today I am wise, so I am changing myself."