I'm surprised no one asked what your stats are at. What's your craftsmanship/control/cp? is your level 55 gear HQ and is it melded?
I did all of my collectables grind with level 53 rainbow cloth HQ gear, with some very basic melding (even all of my blue crafter collectable grinding and getting everything to 60) and only upgrading tools along the way, but I also had the level 50 accessories max-melded from pre-HW. From what it sounds like, you might be needing either some HQ gear for better stats or more CP.

EDIT: I also sounds like you aren't getting more than 5-6 stacks. With the gear I was using I needed to hit at least 8-9 stacks. how much CP do you have left over after doing the rotation you described in OP?