The investigations which will help to diagnose the type and cause
for insomnia are Polysomnography, Multiple sleep latency
test and Actigraphy. The therapy
for this condition includes retaining of normal circadian rhythm by non-pharmacological therapy which includes; Photo therapy, maintenance of sleep hygiene.
You need to remain stress free and share your problems with some one close. Warm bath before sleep, mild music, fragrance, comfortable bed will help you.