This part of the circuit still looks wrong. (This is below the previous part). The bottom two MOSFETs are correctly arranged as a mirror, but what is going on with the one on the top left?
It is supposed to pass signal current from the top to the bottom, so it should either be replaced with a P channel device with the source at the top and the drain at the bottom (i.e. a cascode), or left out altogether.
At this stage I don't care about stability, just trying to get a workable circuit.