You may be suffering from androgenic alopecia which is also called as pattern baldness. The hairs start reducing in density at the crown (top) and also the hairline starts refeeding  from the front. This is usually progressive throughout life unless treated. This is usually accompanied by severe dandruff which we call seborrhoea. The FDA approved treatment for this condition is a lotion and tablets. There is no other alternative. No oil or cream will magically work because the hairs are getting miniaturised  and eventually disappearing due to the hormonal effects on the hair roots. Please call me or  contact me with photos using online consult option for proper examination and treatment. Do not start treatment without consulting. I can give guidance and then you can continue treatment on your own.

Hair loss is a progressive problem and if not tackled in time tends to keep worsening over time. There are various causes of hair fall. Read my health feed for a better detailed understanding. https://fit.practo.com/#!/content/28405 After reading this I hope you will be convinced that a proper thorough examination of your scalp from a qualified dermatologist will be advisable for a fruitful outcome. For the accident scar, treatment is depend on the size and texture of scar whether CO2 laser resurfacing would be enough or a surgical excision and skin grafting would be required. Hope this was helpful.