Would cortisone injections be an option for my hair loss or is hair transplant surgery the only option? (photos)

I am suffering from hair loss around my temple area due to previous styling practices that caused tension. I have discontinued wearing styles that cause tension to my scalp. I have found ways to blend my hair to cover my temple area but I still desire for then to fill in. I feel a little subconscious about my tin edges and I also hate that my styling options are limited due to having to conceal my thin temple. I've heard of success with cortisone shots but not sure if it's too late for me.