Sally,

As well as the sound advise to get things checked out medically (You do mean too much to too many not to.); as well as what Mrs. D so wisely mentioned along with the potential of effects of anti-depressant meds, there may be yet another factor.

With the coming of autumn and the day length getting shorter, many people's pituitary gland responds by altering the circadian (sleep/wake cycle) rhythm. That can have an effect on the thyroid-adrenal axis; which manifests as alterations in things like sleep patterns, energy levels, mood and appetite.

If all else checks out medically, going with the flow may allow the body to find its new seasonal balance.
There are also some suggestions to help things along if you feel that this might be going on; mostly it has to do with exposing the eyes/pituitary to bright light at the correect time of day (morning).

http://www.nsnet.org/idacan/sad.html

May you find answers soon and feel well while catching up on some sleep or while wide awake.

With love, Erika