What do you think is the reason for my hair loss, and why does PRP not seem to be working? (Photo)

1) Reasons for hair loss can be attributed to multiple factors: hormone imbalances, nutrient deficiencies, stress, or environmental factors. You should look into having Complete Blood Count (CBC), Complete Metabolic Panel, Thyroid, and Vitamin D lab work to determine possible contributors to hair loss. 2) Minoxidil works specifically to enhance vascular blood flow around the scalp for propagation of hair growth but doesn't necessarily have an effect on hormone imbalances. 3) The effects of PRP can be tampered by multiple factors, one being the manual preparations of the PRP itself. Though PRP is referred to as the 'liquid gold' of hair therapies, it's not so much the yellow color that's most important, but rather the cloudiness of the product. The 'cloudiness' is attributed by the suspended platelets of the plasma from which the essential growth factors are derived. I strongly suggest that you seek Trichoscopy examination of your scalp to assess your hair loss condition at the finite level. If you are experiencing abundant follicle miniaturization, therapies such as PRP, simple dietary changes, nutraceutical supplements (Nutrafol) should provide some improvement. Laboratory panels are important for you to determine possible imbalances or deficiencies. Best, Dr. Anil Shah

Thank you for your question, This needs an in-person evaluation. I suggest seeing a hair loss expert now to evaluate and go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone and/or hair transplantation. See an expert. Best, Dr. Emer

I think you should first go to your regular doctor and get some blood tests done to check anemia thyroid etc in detail looking for the reason for hair loss. If there is an untreated cause that would account for the lack of response from current treatments. 
Also lots of photos helps. Sometimes these treatments help you retain what you have preventing further loss. That is more difficult to discern. 
I wish you the best!