I would imagine that the reason for your hairline thinning is that you constantly are wearing braids or weaves. The installation of these requires braiding which is often done with an extreme amount of tension and pulling around the hairline. This is called traction alopecia, hairloss from pulling the hair out at the roots.
For the next 3 months at least, avoid any braiding or weave installations, and simply shampoo and treat your hair weekly to strengthen and repair the hair. Dark and Lovely Anti Breakage Healing Treatment is perfect to do the job. Should you want to have a weave or braids in future, ensure that your hairdresser does NOT pull or create too much tension when she braids your hair.