linking current sensing feedback with variable DC-DC output question

[john23]

Hello, As you can see below I have a simple Mosfet where a current goes threw R1.(its 0.1Ohm)
In real life my mosfter is a power amplifier PMA5-83-2W shown in the link below and my V2 in real life is a relay system shown below.
The relay outputs voltage "V2" on a certain time period where all the feedback action needs to taken place.
In the final united photo below I have the current sensing chip and the relay with variable output.
I want some how to get the the relay system of LTC1261LCS8 to change the output voltage according to the feedbacl from the current sense chip LT6119.
Is there a way?
Maybe some feedback mechanism that will control the output of the DC-DC?
LTspice files are attached.
Thanks.
https://www.minicircuits.com/pdfs/PMA5-83-2W+.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/611912f.pdf

[xvr]

You still trying solve simple problem in a most complex way
You don't need regulated DC/DC for negative voltage. Maximum load current of this circuit is 2.5mA. Just use negative voltage (you say that you have -12V in system?) for power opamp and get required negative voltage from it's output. In this case you also don't need switch and discharge on this voltage rail.

Another point - gateing of 12V supply also wrong, you should use high side switch. You can try to find switch with current sense and get rid of separate current sense circuit.