If you are losing hair it stems from Internal factors. Usually one loses hair due to change in diet, stress, illness and sometimes even seasonal. I would start by getting an appointment with a doctor and checking your Iron and Zinc levels, also possibly your thyroid.
I would then seriously look at my diet and start your day with protein, possibly a multi vitamin. If stress is a factor then I would learn to do some meditation to control anxiety, only then can we worry about products that we use on the outside. There are amazing products out there that assist in hair growth by getting the scalp into optimal condition, such as Kerastase Densifique or Loreal Seroxidyl. Also results take up to four months to see from any of these programmes.