Hi You seem to be having chronic telogen effluvium. This condition is common in people who move to a new city, have thyroid problem or if your dieting off and on. If you are seeing thinning of hair and scalp is visible it is time to seek professional help. Please meet a dermatologist so they can advise you on the best treatment plan. Shampoo are only meant to cleanse the hair and cannot help with the primary cause of thinning.  However some shampoo add volume to the hair. Please ask your doctor for the same