Left eyebrow immobile after endoscopic facelift 15 months ago, what can I do?

I had a facelift 15 months ago, and since then, my left eyebrow has been immobile. It has a little movement at the end of the brow, and that’s all. I have lost my facial expression, and I feel so worried that it will stay that way. I started physical therapy and electrotherapy. I have used Proserin and Nuclo injections, but none of these have helped. What can I do?