Kneecap pain and one week til NYCM... oh boy. Suggestions please!

Throughout my training, I've had slight knee pain occasionally and sporadically. It's in the front of the kneecap, and due to its symptoms, it seems like patellofemoral pain, or "runner's knee".

I've been foam rolling/tennis ball rolling my ITB, quad, and calves to attempt to loosen the surrounding muscles, icing the knee post-run, applying arnica cream, and getting ART on it (Graston). When running, I think about using my glutes so my hips/ITBs aren't taking the brunt of the pressure and hence pulling the kneecap out of line and create tracking problems.

With one week to go til the NYC Marathon, I ran my final long run of 12 miles yesterday and completed it at my usual pace, able to maintain my form. There was discomfort/pain (not sharp pain, but I would label it as pain) about 85% of the time in my kneecap- ranging in severity, but never so bad that I had to alter my form or stop running. It never got worse and worse and worse... it was just present... just there. Keeping a quicker pace with shorter strides felt like it kept it at bay and made it better. Today, though, I feel pain/achiness in my knee and have been icing. So I'm concerned...

So my question is... what do I do this week to prepare my knee the best I can for the marathon? I was planning on 2 small runs to loosen up- should I just do the elliptical instead? Wall sits and strength to attempt to get it to track properly? Should I use a strap beneath the knee? (I know, nothing new on race day...) Please, any suggestions are more than welcome. I'm a little worried with one week to go...