Should I have filler for forehead atrophy after cortisone Injection?

Hey, sorry in advance for no pictures! I have atrophy on my forehead from a cortisone injection. It has been there for six weeks. I have had 3 saline injections to no prevail. I am wondering if I should do filler or just wait. My derm told me to let her know when I am ready for filler. I am hoping the saline will work as I am terrified to get an HA filler due to over correction or unfortunate side effects. Advice would be greatly appreciated. Thank you so much! Again sorry for no pics. :/