There are lots of reasons why one might stay up all night, based on various diagnoses; if you are bipolar or depressed, etc., they can be symptoms rather than self-injury. I would talk to my therapist and doctor(s) and try to take better care of myself so crappy weeks can be better handled and don't get out of control. Staying up all night usually does not immediately injure or help anything, SI usually serves an immediate physical purpose.