I take the opposite approach--I could give a sh1t how much interest a girl has in me. The only thing that matters to me is how much interest I have in the girl. The more interest I have, the more engaged/motivated I'll be, and (usually) the better the result will be.
There seems to be a misconception, probably based on the principle that 'whoever cares least controls the relationship,' that interest level can't be mutually high. But interest level =/= investment =/= attachment =/= loss of frame (at least it shouldn't).
But your frame is fvcked from the get-go...you're looking at things from the frame of: how can I make this girl more interested in me? She's already the prize--but you're looking for ways to act like she's less of the prize, which reinforces the frame that she is the prize. You thus cannot be high interest because you might 'lose' her.
Try approaching things from the mindset of: How can I make this more interesting for me? (since we often give girls too much credit for whatever idealization we project on them, it's helpful to be consciously aware of this process). Or on an even bigger picture: What can I do right now to make my life more awesome? Prioritize respectively.