He is looking at the clock repeatedly, feeling more and more frustrated as the time passes as how it is getting late and her effort to sleep is going in vain.
Effort? can anyone put an effort for something which is a self programmed function of the body -mind complex?

Does one put an effort to breathe, make the heart beat or digest food?

Try doing this at home. Try putting a conscious effort to digest your food, be aware of it entering the food pipe and the stomach and then liver metabolizing it. You will end up with indigestion!

Effort is interfering instead with something which is automatic!

So your struggle to sleep is the biggest reason why you are unable to sleep!

Do not try to sleep

One should have courage to wait for the body to tune itself back during a temporary phase of insomnia due to some stressful/emotionally challenging situation.

One's continued stressful approach in life or excessive seeking for stimulation all the time may have finally resulted in the overworked nervous system being so stressed that it now has difficulty in tuning itself off.

There are people who have not slept at all in their entire lives, but there daily activities are not hampered at all, so

Get rid of these conditioning that shortage of sleep will have an ill effect on the body, though difficult, if you let go of this you will be happily surprised to know that this conditioning or belief was creating most of the bodily symptoms!

Chronic insomnia which has developed after a traumatic emotional experience may need a help from a professional like counselor or a hypnotherapist.

Sedatives decrease the brain activity by depressing the C. N. S, making one lethargic/drowsy with reduced mental efficiency and host of other side effects.

The induced sleep is more of non REM type (REM is supposed to be a deeper and more refreshing phase and is characterized by rapid eye movement)
Drug resistance develops soon and the dose gradually increases and so does the dependance and its withdrawal symptoms. And finally one must realize that they are not the cure
So it is better to take them as as a one-off thing, at times of acute distress or urgent need to sleep.

Some other tips which are of secondary help.

1. Do not keep a clock/watch with you in your bed room.
2. Avoid heavy dinner or supper, keep your digestion in check.
3. Do not immediately go to sleep after dinner.
4. Avoid caffeine based drinks esp coffee or if you must have it, take it before evening.
5. Try putting off gadgets like mobiles, T. V, games, magazines etc.

Lastly in a nutshell, do not get overworked if there is reduced or delayed sleep, that will act as a stressor which will prevents sleep, have the courage so as to not to sleep at all. Do not anticipate tomorrows after-effects. Surrender to the intelligence of your body, it will take care of it.