I am very upset with my hair thinning. I have hemochromatosis. Is biotin the best option I have?

In my opinion, you should be evaluated by a hair loss professional. They will do a good history, examination with magnification and possibly biopsy and blood work. Hair loss and hair thinning are often seen with hemochromatosis. Your physician will determine if it is solely the hemochromatosis or if there  are any other diagnosis present. Minoxidil, low level laser and PRP  can  usually be helpful.PRP hair MD.com

No, biotin is certainly not your best option. In fact there is limited evidence biotin even helps at all. You need a full examination to determine the cause of your hair loss. It may be completely unrelated to your hemochromatosis. Depending on your health, current organ function (especially liver) and other factors - a variety of options are likely possible. You need to see an expert to first get a formal diagnosis.

Biotin is certainly not your best option - it may or may not be helpful to take supplementation.  It is best to see a hair loss expert who can evaluate you with lab tests and take a full history and examination of your scalp to determine all the factors involved in your hair loss.  There may be multiple options you can consider, but an accurate diagnosis needs to be made first.   Good luck!