The cause of almost all modern diseases are inflammation, oxidative stress and malnutrition (which includes high calorie malnutrition).
It's impossible to isolate a single factor as having a single cause—rather it's like: "ABCDEF interact together to cause all of XYZÅÄÖ". To think that you can find "the silver bullet" is mostly masturbatory thinking. This is what Western medicine aims at, but it's misguided.
Treating depression, anxiety, asthma, eczema, diabetes, allergy, and so on, must begin with removing inflammatory factors from your life and introducing regenerative ones instead. Start here:
Some more specific pointers:
Consider that in all animals except humans, hair loss is a sign of disease.
Being genetically predisposed to hair loss doesn't mean it has to happen. In fact, you can slow, stop, or even reverse hair loss by preventing oxidative stress, inflammation, mineral dysregulation, and consequent hormonal dysregulation, which are all factors driving hair loss.
The causes of the above are multiple. Lifestyle stress is a significant factor and should be avoided to the best of your ability. However keep in mind that a diet that accounts for all micronutrients will improve your ability to handle stress.
See the section about free iron.