How do I even build up the 6hour stamina for advance?

So in my coaching we just had an advance exam on sunday and tho questions level werent advance level so technically it was just mains paper with advance pattern (these ngas groped my ass by giving advance ke questions on like fking mains paper bro which was supposed to be 11th revision test , I dont know what they even trying to do with the tests man). The one thing that is bothering me is the fact that I litreally cannot sit and give paper 2. Legit on sunday , we had class before the paper and we were supposed to give paper 2 at home . But my body just refused to give , I couldnt even hold the pen properly . I thought I would give it today but today I went to school , had a cs exam . And also went to coaching . How the hell I am going to do this shi on D day jab actual advance ke questions hoge and advance ka paper hoga...

Seniors kuch upay batado ;-;