are you drinking enough water? you should be drinking 2-3 liters a day. 3 liters if you're going to try the p&b shakes at the same time. I got really constipated at first and the P&b shakes didn't help though, in the end it just started again all by itself - but you might want to try eating things that are supposed to make you go, like prunes, or take a spoon of good quality olive oil a couple of times a day? If you're anything like me, going to the bathroom is probably your first priority right now.
Or even better try to find a colon hydrotherapist in your area, that would relieve the immediate problem of constipation, which may well make the other symptoms less bad.