Avoid exercise. Visit physiotherapy centre for  treatment

Any therapy taken should be as per the correct diagnosis of the problem will help.If your hamstring is tight then you must be getting a lot of back pain also so strengthening the back muscles should be done as well.Besides that proper intake of vitamin D is necessary.

Simply sleep on abdomen most times in night. 15 days

Hello Proper assessment is required to dig the root cause of your pain whether it is muscular or neurogenic in nature, accordingly your treatment can be planned. I would suggest you to take rest for 2 days, do hot fermentation on lower back as well as on legs. Do stretching exercises for legs if you know any.

U must be having sciatic nerve / neural tissue tightness it needs to be released by NEURODYNAMICS or nerve tissue mobilisation

A common cause of tight hamstrings is exercise or another form of intense activity. Exercises that put substantial strain on the hamstring can lead to tightness. The hamstrings are more likely to feel tight after resting, for example, the morning after exercising. Having tight hamstrings can also increase the risk of injury. For better results and proper exercises should be in guidance with an experieneced physical therapist. IFT for a week and then exercises depending on the condition will be suggested.

Take hot fomentation first for both legs

Before letting you know the exact treatment one needs to analyze the root cause of the problem.