Are you getting at least eight hours sleep a night?
Have you had a recent medical done, check blood iron levels.
Are you eating properly in general?
Are you stressed over anything?
All of the above affect feelings of tiredness, also the weather is not helping, I would like nothing better than to hibernate till this winter business is all over. Fajr here is at 6:30am Maghrib is at 4:10!!!!!!
Loads of duas, hope you feel perkier soon inshallah.