Folded cascode op amp

My op amp is producing very low gain. Please can anyone see where my mistake is? I've done a DC analysis but I can't see the mistake. Thank you.

The bode plot between input and output signals is -6.1kdB and 45 degrees constant:

 

Can't make heads nor tails out of that schematic. Too much clutter, poor choice of colors on a black background.

 

There is not enough voltage at the gates of M2 and M3. As a consequence, after the voltage drop M4 and M5 saturate and can't pull enough current to forward bias M8 and M9 and they saturate as well.

 

Sorry for the late reply, I thought I would get an email notification for this.
I was wondering what books or online resources you used to be able to understand what to do? I'm really struggling and I don't know what initial steps I should take to go about creating a circuit design like this. Like which transistors should be in saturation, how I can decide on the bias voltages and currents, other than just running a sweep and choosing the best values - I am not using logic, just repetition to solve right now.
Thank you.