Everybody has to know themselves and the way their body works. SM indicated correctly that learning all night is a minhag, not a chiyuv. I’m suree noone argues that point. The OP indicated he had an infection and hadn’t slept for some nights and would be unable to learn all night. rt brought up a red herring and Sam2 didn’t speak to the OP’s concern.
Sam2 RSZ siad the minhag is worth hurting your learning… not hurting your health.