Hi, I'm Emilie, and I'm 12.
I'm very sorry to hear about your diagnosis. It affects 2% of the female population. Hair loss is one of the symptoms.
Moisturize your hair. I recommend cantu Shea butter cream leave in conditioner, wet your hair and put it on your roots and the rest of your hair about 2 times a day-Before bed, and after you wake up. No blow drying or heat. Coconut oil is very good for your hair also. Keep eating foods that are good for you, and drinking water helps your hair as well. I would also say to take keratin vitamins for your hair and nails. Use creamy and moisturizing organic shampoos.(whole foods has a great selection).
As for brushes, I would say to use a tangle teaser brush, they sell them at target or online stores. Or use a simple wide tooth comb.
Please message me if you want a list of products that will help your hair