It's probably the yeast. Do you have a way of cold crashing? You can also use gelatin to help drop more out of suspension. Don't try to get every last drop out of the bottle either, leave the dregs. Watch as you pour and when you see the sediment starting to make it's way up the neck stop pouring. That could help you out for now. Honestly though, your body will adapt in time and you won't have problems anymore. When I first started brewing I would take a Beano before and a Gas-X afterward if I planned on having more than 1. Now I can drink as much as I want and the only result is a bigger belly! As it so happens, a bigger belly is the single biggest argument against kegging. If you have fresh cold beer on tap you WILL drink more of it.