So, your most likely candidates are meds (both of which could cause drowsiness) or depression/anxiety (discuss adding in an SSRI or additional antidepressant)
Other than that you can look at things like hypothyroid, anaemia, iron, vit D. it would be worth while testing to rule them out
You can also add in a multivitamin, eat well and make sure you drink enough, small amaounts of exercise regularly... I really fell like I'm channeling my sister who is a nutritionist and naturopath ...
If this is really affecting you quality of life, you should discuss it with your doctor and don't let up till things are improved