98 RWD blazer 166k miles. Recently it makes a slightly high pitch noise when accelerating from what I assume to be the transmission trying to shift. The noise is most prevalent at lower speeds like around 15-20mph and 35-40mph; also it seems difficult to get up to highway speeds. At lower speeds it almost feels like the car is surging and difficult to shift. It doesn't slam into gear, though has in the distant past. Reverse works perfectly fine. The transmission fluid level is fine though a little dirty.
Im getting codes P0122 (Throttle/pedal position sensor A circuit low input) and P0336 (crankshaft position sensor A circuit Range/performance)
Help! is this the grim reaper coming to collect my transmission?

It has other problems which I think are unrelated to this new transmission shifting issue namely an exhaust leak, coolant leak, and a pernicious but incredibly slow oil leak. I probably need new injectors and head gasket for this but doesn't seem too sever and have yet to see coolant in the oil or vice versa. But I am an idiot so idk
Additional codes that have been showing up for years now are P0171 bank 1 system lean, P0174 bank 2 system lean, and P0305 cylinder 5 misfire