from the the symptoms you describe I would say look into the possibility of SAD, cabin fever. In any event check your sleep patterns. If you feel night time sleep is unrewarding or then it won't be helping any. It is sometimes easier to readjust sleep patterns by delaying the cycle (get a full 8 hours) gradually until you come round to the achievable and regular sleep time. Not that working people can fit that in but remember we humans have a natural diurnal cucle of 27 hours so that even if it is messed -up a bit the earth day will reset it. That is the other clue - get some really strong light for a few hours (daylight is deceptive the eye is logarithmic and daylight is very strong). Doctors will tell you about seratonin levels and there are pills but some foods have it. It might be worth investigating such foods - start with carrots.
Oh - and there is always Mudcat .