Do you use steroids? I don't judge, but if you are balding at 19, mention anabolic diets as well as weightlifting and cardio, this might be due to unusually high testosterone levels.

If you're partial to a dbol here and a shot of test there, you definitely should read up on anciliary drugs and more balanced cycles.

Quite often when sports people bald at a young age, anabolics are involved.

Then there is the grisly possibility that you may have unusual levels of free radicals, which may come from an unhealthy lifestyle.

It is also possible you have acute vitamin/mineral deficiencies causing your hair to fall out.

No matter what the culprit is, I recommend you to take a strong multivitamin with emphasis on vitamins C, E and Zinc, and this every day.

Aside from that, unless you are directly causing the baldness through steroid use, I'd like you to see a doctor about this. Hairloss can be a symptom of many things.

The multivitamin & mineral supplement advice stands.