Congratulations on the Guts to take the bull full on. It is a a great way to learn, but....yikes, couldn't you have tried something a little less difficult for your fist adventure? Like maybe....ummm....Brain surgery;-):-)
Before you worry about the box being locked up, you need to pull it apart one more time and inspect the races of those bearings. Please check and confirm there is no discolouration of the bearing surface inside and no pitting of the little Balls. Marks on these surfaces is usually the first thing to occur from water
contamination and at best the box will whine when running and worst, the bearings will fail and could destroy something more critical. It is easier to replace the bearing now, than go through it all again later.
The locking up part, it could take a bit to turn it. Have you any tranny fluid in it, or is it still dry? If it is dry, the plates could be gripping too much. Or...
You may have a thrust washer or spacer on the wrong side of a bearing or gear
and the result is one gear is not coming away from another completely. It's hard to know without seeing. I assume you took notes or photo's of where everything went as you removed parts
. The only other thing is to get a manual and go step by step. Take a look in the Manuals
section and see if one is there for it. Mute point if you have already done that of course.