I'm sorry to hear you have such health problems, but I'm afraid I can't reccomend products as I haven't tried any.
But what I have tried are nettle rinses. I had hair loss issues several years ago and I was persistent with the rinses. I think it helped a bit to strenghten the existing follicules and roots of hair, and it darkened my hair a little.
If you would like to try this, I will give you the recipe.