Before seeking out the 'cure', you'll first want to determine the cause so a good place to start is by talking to your GP and ruling out possible underlying medical causes. Blood tests that should be considered include a full blood count, ferritin levels (iron stores) a full thyroid panel and a female hormone panel.
Addressing possible nutritional deficiencies is also key. The nutrients that are most critical include protein, iron, zinc, silica and B vitamins. To ensure adequate intake of these, eat a wide variety of protein-rich foods, including fish, red meat, eggs, beans, lentils, nuts, seeds as well as green leafy vegetables. If stress levels are high, they'll need to be addressed too – experiment with stress management techniques, including exercise, meditation, yoga or talk therapy.
If underlying medical conditions have been ruled out, diet and lifestyle changes are not helping and/or you feel your hair loss is chronic, then it'd be wise to seek the advice of a registered trichologist as soon as possible. A trichologist is a hair and scalp specialist who is qualified to both diagnose and treat various scalp and hair conditions with a variety of hair loss treatments, including steroid injections and laser light therapy.