Both the inputs to your error amplifier are actually the outputs of your system.
VLED and the Current.
If VLED is 0V, then the Current and hence the INA210 output is also 0V.
Therefore, both the inputs of the error amplifier are 0V, hence its output is 0V.
This would mean that the PWM would never generate and the MOSFET would never turn ON which will in turn keep your VLED always at 0V.
Your system can be reduced to
VLED = [VLED - {VLED-(I×R35)}×GainINA210] × System Transfer Function
The problem here is that your system could have many solutions and the above 0V solution is also one of them.
This is because, like i mentioned in the beginning, you have used the outputs of your systems as the input of your error amplifier. There is no actual reference for the system to compare against which was there in your original design.
This is just a top level understanding, I have not gone through your circuit or transfer function in detail.