Hi Elaine,
I don't know if you have a regular meditation practice. But meditation practice will help you cultivate mindfulness.
Texts like the Satipatthana Sutta and Mindfulness in Plan English can help you develop a practice--indeed they are invaluable resources. However, at the end of the day (and you may have already heard an analogy like this) they are just the 'maps' for the path. You will have to eventually tread the path yourself.
If you don't already have a practice, you could look up a dhamma centre near you. Check out this directory:
http://www.buddhanet.info/wbd/
There are also meditation guides online.
Also, it might be worth taking a step back here to note that insofar as papañca is 'the proliferation of discriminatory conceptual thought', the mounting confusion you have about mindfulness, the proliferation of questions you have about mindfulness ('whether it is this or that, etc, etc), is itself a kind of mental proliferation. This, then, raises the questions, 'To what extent can conceptual thought undercut papañca, if conceptual thought itself is borne of papañca? Is there a way of allowing the mind to catch itself thinking?' I suspect the answer lies in the cultivation of mindfulness. I cannot stress the word 'cultivation' enough because it suggests that mindfulness is best understood not as a thing or state but as a
process, and a rather dynamic one at that.
EDIT: I'd also like to add that if mindfulness is something to be cultivated, then one should be patient for it takes time and practice. All the best.
Metta,
zavk