Sounds like you're using a sledgehammer to put in a thumbtack. A less powerful tool might be the answer.
A pilot hole will allow the screw to be driven more easily, and may solve your problem.
If the driver has a variable torque setting, try setting it lower. That way the clutch will slip before the screw breaks.
If you're using phillips head screws and they're stripping, try using Torx or Robertson drive instead.
You don't want to use a hammer drill when drilling wood, or driving screws. Hammer drills are only for drilling masonry, and should only be used with bits designed for them.