You are suffering from Insomnia of recent onset with underlined anxiety as the major reason. You should avoid pills like Nitrazepam which can become addictive. If you are already on 2 tablets daily night then reduce it to 1 tablet for 10 days and then stop altogether. Meanwhile you could take a tablet of Eternex (Melatonin) 3 mg daily before sleep. Its a safe and milder medicine without any side effect.
You should also take sleep hygiene precautions. They are:
-regular exercise,
-proper time of meal,
-avoidance of coffee and tea after 6:00 pm,
-regular time for bed,
-maintenance of worry/sleep diary and
-positive attitude in life.