Hello Welcome to HCM. As you had worked at the call centre in night shift for a long time, this has altered your sleep-wake cycle. Our body is set to sleep in night naturally, but in your case, due to job the body rhythm has been disturbed. There are few tips which you can follow to get back to normal: Have a good daylight exposure. This will help your body in returning back to normal rhythm. Avoid daytime naps. Donot take tea, coffee, chocolates, alcohol, fatty meals at bedtime. If you donot get sleep withinin 20 minutes of lying onto the bed, donot try hard to sleep. Just leave the bed and take a normal walk in you balcony. Practice relaxation exercises like deep breathing, yoga etc. Donot do vigorous exercises before going to bed. Never keep lying idly on bed. Use your bed only when you sleep. Donot listen to loud music at bedtime. Also you can try tablet zolpidem 5mg for sleep. But it might cause some hangover next day. Hope this helps you. Thanks.