Airline flying with several overnights a week definitely takes its toll on quality of sleep. It gets worse when you have different time zones to consider if you fly international. Everyone has their own way of dealing with it, but I would refrain from using OTC medicines or alcohol as they both can become addictive. It's quite normal to remain awake for a while when you get to your room. Especially if it's late in the night. Good diet and regular exercise as well as darkening your room etc etc as has been suggested does help.