Hi, since sleep apnea has been ruled out, the tiredness is likely due to something else. Common causes include
thyroid imbalance, anemia,
Vitamin B12 or D3 deficiency, or even low-grade depression or chronic fatigue.
A basic blood workup (CBC, thyroid, B12, D3, blood
sugar) would be a good starting point to find the root cause.
Next Steps
Feel free to consult me on Practo with your reports for a proper diagnosis and treatment plan.