Tips on bike position...

Lard - this is more an academic view than learnt through time on a bike. But it could either be you should adjust your bike, and your handlebars may be too low etc. To do that, you can add in a stack, a small ring that raises overall handlebar height by a few centimetres, or actually rotate your bars toward you a fraction, which raises them a little.
Either that or you're not riding in the correct position. Andy will know more I'm sure. But you should ride using your core muscles, so you arms are resting on the handlebars, but not actually taking any of your weight. If you're cruising, you should be able to lift them off the bars and not fall forward.
Also, there are 5 positions you can have your hands on the bars, perhaps you're riding in the aggressive climbing or sprint positions instead of siting up more for cruising?
I know all this cos I've been told it or read it in a book. So no idea how useful it actually is...