I've noticed that my stouts and especially my cream stouts need to be dispensed at a pretty low psi (3-5) to not be overly 'heady'. I don't necessarily think that 14 psi was too high to carbonate with, but you didn't say how long you held that pressure. I force carbonate at between 20-30 psi depending on the style, but only overnight. From then on I let the keg sit at it's dispensing pressure for about a week and that seems to work good for me.
What you can do to help remedy this particular batch is reset your pressure to about 5 psi and let it sit for a few days, all the while "helping to relieve pressure" by having a few pints. This will help, trust me.
