bend that washer. there should be 2 tangs on it....bend one tang back and away from you over the inner nut and the other tang toward you over the outer nut.
first, thoroughly inspect the threads on the nut and on the spindle to make sure that they are not damaged. the spindle on the drivers side is a left hand thread....so lefty tighty-righty loosey (left to tighten-right to loosen). if that doesnt work, use the nuts on the passengers side spindle (the ones that fit) on the drivers spindle and see if that works.
good luck. B)