In addition to the regulator check if your shutter is fully open. My 5PSI regulator is not enough for a 14 gallon boil in a 20 gal pot without a heat stick, but the 10PSI should be fine.
You could try a low attenuation yeast. Maybe Irish (high ester). Da Yoopers has an OG of 1.060. With Irish (or Scottish), you would be around 1.022 +-3 or so after bottling.