Yeah, i used film cap for C7 1uF, thank you for the help .

Yup, changed C7 to 1uF, and used tantalum for the others, thank you for the help.

Thank you for the help guys, it really helped me, i hope that this question will be useful for other people also.

I just got permission to do whatever is needed to finish , so boosting the voltage, then messing around with the constant current and stuff should work, thanks for the advice .

Hmm, i was initially trying to avoid using higher voltage, and then stepping it down, however, it actually sounds quite interesting. For example, maybe stepping up the voltage up to 30 Volts , and then probably using a much simpler LM317 configured as a constant current mode ? , still would need to ask the profs whether we are allowed to do this ( they initially wanted for us to figure out / find out a solution for the original problem with using 12 Volts) , thank you btw.

So basically it has to have a virtual ground , instead of connecting it to the ground of a DC supply ?

@SteveG Thank you so much for the link for the explanation on the switch, it was very helpful .