Not much to type here, but I completely redesigned my constant current circuit. I replaced the current sense amplifier with a programmable gain amplifier, added an ATMEGA328P microcontroller, a pinout for an LCD screen, a pinout for I2C and ICSP, a rotary encoder for controlling, a heatsink, and other necessary components.
Here is the final schematic:
And here are the circuit board designs:
Link to my files and Oshpark project:
Mini Circuit 1: Constant Current Sink – Update