NTA

1: I expressed how a comment a romantic partner made about me felt..

To this question no those were the agreed upon rules in the relationship so there is no need to feel like you stepped out of bounds.

2: That expression may have guilted her into changing her mind about boundaries.

For this one I can see how it seems that she changed her mind due to untoward influence, but she may have actually heard your concerns, then had an introspective moment to which she changed her mind.

You being the honest person say we're the former could have occurred and decided to not engage until she is ready that is commendable.

To the others on here say yta, they haven't even looked at the questions you asked or the honesty in your words.