Slips into neutral and whining noise

I have a 98 Durango SLT 5.7l Magnum 119k. When driving into work all of a sudden at a stop sign it would not move. I pushed accelerator again and it went then not 200 ft slipped back to what feels like neutral and rpms rev and soon after would pop back into drive. Luckily was only 3 blocks from work. After work it wasn't wanting to go into any gear even thought you could feel it go into gear but it wouldn't move. Again give it gas until it kicked into gear. Now sitting in my garage after towed home and same thing but now when put into reverse there is a loud whining noise or grind (hard to explain). Put into neutral no noise. Put into drive and the noise is back but not as loud as in reverse. Mind you I can feel it go into gear but it won't move. No engine light, no codes. Prior I have had an ABS and Brake light come on once in awhile upon start but now that don't come up during this whole ordeal either. Also gear shifter on dash is slightly off in some positions and has been and no reverse light for awhile. It only has 119,000 miles and has had regular maintenance from day one. Aside from what I listed but my mechanic was not concerned about those. Well taken care of and this was sudden no warning of tranny issue slipping or rpms revving....not a thing. Please any ideas? I have seen a whole gamet of ideas but I can test or replace all the solenoids, sensors you name it but would rather not waste time and money and figure out first time around. I did see something about filter could be lose or fell out. There is Tranny fluid all over under and that started out of no where when it was laid up in Spring until the next winter season. But tranny level is not low, not burnt, looks and smells fine. My husband just said it sounds a lot like when the power steering is low or going out in a vehicle but more aggressive when put into Neutral.