01 S4 6speed problem

Got an 01 S4 w/6 speed. Trans was shifting smooth, came to a stop, went to take off again, and all of a sudden it was hard to put into gear. Very difficult to put in all the gears. Can't put the car in reverse at all, it will just stay in neutral. Didn't hear anything break, no warning signs. Any ideas what it is, is the trans done, what broke, any common 6 speed problems? Any help would be greatly appreciated. Thanks!

fluid level? not sure if you can check this w/o a vag though... i forget.