This is what I've done several times and its always worked great. Disconnect the co2, bleed off all of the co2, you'll have to do this several times over a couple of hours. After the last bleed off, reconnect the co2 after you've confirmed that the dispensing pressure is set correctly. Wait a week until it recarbs to the correct pressure, or use the shake or roll method of force carbing. It sounds like something is messed up with your regulator.