How to study for more than 4h per day?

Exams are 2 weeks away, and i am super behind so i need to study more than I currently am. With pomodoro technique and proper breaks i can manage at most 4h per day before i dont feel like studying anymore or lose focus. What can i do to increase this? Id appreciate practical advice pls.

I study 25m, with 5 breaks and after 4 cycles of this i take a 30m break.