the circuit you have shown is a folded cascode .I suppose your currents might have been screwed up. Just check if you are pushing enough current in all the stages. Also one way to get vds to distribute equally is to make the pmos size 3.5 times that of an nmos, this is from my experience of designing a folded cascode.Also try to get the overdrives of all transistors to around 100-150mv, this will also boost your gain and also help your operating point .Better post an image with the sizes and also with the region of operation shown in the figure.
amarnath