03 T&C goes into limp mode and throws engine codes

My 2003 Town and Country with roughly 180,000 miles does some pretty hard shifts between 2 and 3, and 3 and 4. It will also vibrate around 25/30 mph, right where the 2 to 3 shift is, if you hover around that speed and don't accelerate though the shift. When I first got it around 5,000 miles ago, the transmission was mostly fine. I had to replace one of the axles (and made sure to properly top it off with atf+4!) However, now if I drive it around hilly areas, it'll eventually go into limp mode on the the 2 to 3 shift, and then it keeps acting up until I park it overnight.

It's throwing a P1776 for the overdrive solenoid AKA the solenoid switch valve latch in the low/reverse position
And a general P0700 for the transmission control system
A P0731 for gear 1 ratio incorrect
And finally P0846 for the transmission fluid pressure sensor/switch b circuit range

The shifts might be hard, but no grinding, and I've only had it momentarily slip once or twice on the coldest days of the winter trying to leave my house.

I'm prepared to need to seek out a replacement, but before I jump to that, I wanna see if anyone can explain these codes to me better, and maybe it's something simple(ish) like the solenoid pack? Or it could just be super gummed up, not sure the last owner did a very good job with maintenance.

Any help is appreciated, feel free to ask any questions that might help!