Stripped manual Tranny Plug...HELP Please!

So the other day I decided to treat my 95 taco with some new fluids. I had planned on changing the tranny, transfer and diff's with some new synthetic gear oil. Started off in a great mood but quickly gave myself a pounding head ache.

The problem...I stripped the female threads on the transmission drain plug. At first I was in disbelief until I looked up the torque on the plug AFTER and realized it was only 20 or so...not a lug nut! There went the $30 in new fluid.

Got a new m18 plug from the store just to give it a shot. Thought it was going to work but when I tightened it, she must have stripped more cuz what was a drip before, turned into a pour and out came the all fluid.

I'm now stuck...Can't find an oversized M18 plug....can't find a M19 plug or tap so I can move up a size....Help! I've never tapped anything and am quit nervous: This is my baby we're talking about. Even if i tap it the next size up...like i said, i haven't found any place with a m19 plug (i know that's equivalent to 3/4 inch and still haven't found it). I need someone to point me in the right direction and let me know where to find/ what exactly I need.

Also, I believe the original plug is M18 x 1.5 with a 16 thread pitch. Does that mean I'm looking for a M19 (or 3/4 in) x 1.5 plug with a 16 thread pitch??? I'm officially lost on what to do!

Thanks.
Matt