Hi sweetie
I am not a professional but I would like to throw in my two cents. There are three things you can do to prevent hair loss.
The first one is taking hair supplements, the second one is buying appropriate shampoo to boost hair growth and the third is to massage your scalp regularly with oils to help bring blood flow to your scalp.
*For supplements I recommend biotin. A lot of youtube gurus are taking it. You need to drink a lot of water or else it can give you acne (but hey, when i received my corticosteroid shot, I had bad acne for 3 months !)
I am taking a multi vitamin supplement enriched with biotin and I have had no side effects so far. I also take fish oil, particularly, cod liver oil in capsules. I used to have dull hair with some shedding ( handfuls of hair left in my hands at bath time). Thanks to those hair supplement I take, my hair is now gorgeous ! I credit it to biotin. Biotin is a co-enzyme and a B vitamin, it makes hair grow long. In just 3-4 month I went from shoulder length to middle of the back length. My friends noticed the rapid change ! But I also massaged my scalp a lot.
Make sure also you do not have iron deficiency. Corticosteroids cause iron deficiency which in turn causes hair loss. I had this issue because I was once a vegetarian and I was eating enough iron rich food.
I was prescribe an iron supplement and changed my diet a bit. Now that I eat fish and now that I take my iron, my vitamins and my biotin supplements, my hair is far better.
But I am no doctor, so you should ask your doctor about taking supplements as you are currently being treated with medication.
*A good shampoo is organic, without any of those bad chemicals, and without silicon (silicon will clog your pores and prevent a good oxygenation of your scalp hence furthering hair loss). You can find some good, cheap shampoo on the website Iherb. I recently purchased Acure shampoo with a stem cells technology. Haven't tried it yet, but in the reviews, people were raving about it.
I would steer clear from hairsprays, no matter how tempting giving some body to your hair with hairspray might sound. Hairspray will suffocate your hair as well.
*Massaging your scalp: Have you heard of the "inversion method" ? If not, you should google it. It is excellent to promote blood flow. It will leave your scalp all tingly and you will see results quickly. You need to use oil to maximize the mechanical effect of the inversion massage. I suggest using coconut oil, or sesame oil, or olive oil (100% pure virgin olive oil, the one you would use to cook with!). Those are oils I use every week. The oils need to be so natural you could actually eat them.
Once again, I am no doctor, but those steps worked for me. You should speak with your doctor and see if you are not experiencing vitamin/mineral deficiency due to your treatment. I also think that the solution lies in treating your hair and finding the root of the issue rather than in concealing the issue.
Good luck.
Note: Do not stress about your hair loss, it will eventually get better, it did for me. Patience is key.