All it will take is one chunk of gear tooth in the wrong place, and you'll have a boat anchor instead of a transmission! Either call a wrecker (and have him tow it with the rear wheels lifted), or pull the transmission and take it to him. The 2nd. and 3rd. gears share opposite ends of the same synchronizer, but it sounds like the 2nd. reduction gear, and possibly the cluster gear are involved. You've got an expensive repair coming, so check into the possibility of a wrecking yard replacement, rather than a repair. The cluster gear, in particular, is a high-dollar piece!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!