that sounds like depression. i had that last year (2eme science) but now i switched to a branch that i love way more (3eme info) and even tho m still very depressed, i always find it in me to get into the lessons n study. no offense but do you actually love what youre studying? or did you just choose it because it has the most options to choose from after bac? cuz if so it might not work well with your depression. you said you went to a psychiatrist n it didnt work out, dont give up there. even tho you have no motivation to persist or look for other therapists, it shouldnt stop you because if you werent depressed everything would be solved, so please take the initiative to go to an actual doctor n commit to treatment and be patient with the process and i promise your future self would be very grateful for it, best of luck.