My trick for three days plus is to work some conditioner into the beard in the shower first. You don't have to use a lot, just leave it there a minute before rinsing it out again. I guarantee your shave will take around half the effort if you use that trick.
This is a great tip for growth a few days or more. I do this as well.
Also, it sounds to me like your lather might need a little help. It may not be slick enough or your not working it under the whiskers enough.