If you didn't use solvent of some sort to clean your chain real good before you lubed it, then the lube you used combined with residual grit and water to make a nasty soup that you are seeing splattered on your rim and that you are hearing when you pedal backwards. Use a good grease cutter like Tough Stuff or Mean Machine and clean it up thoroughly, dry the chain with a rag and let air dry, then lube and wipe off the excess. Too much lube is never a good thing on a bike.