PR is a useless unless you have traffic. High PR does not mean higher position in SERP. My PR1 website generates 150k page impression every month. In mathematics, your PR5 should bring 750K page impression! Does your website bring that much traffic? If yes, then run ofter PR otherwise try to concentrate on actual SEO and generate traffic. All the best.
This was the best answer. But if you need PR6 you need a lot of investment online in order to reach the next number.
What to do next? Do a little pee dance, do 20 jumping jacks, hop on 1 foot for 2 minutes, then for the love of God go play outside for a while, you've been cooped up on the computer for too long.