Having ankle pain 7 months after surgery. They put a screw in ankle and fixed a coalition. Will a brace help?

Talk to your Surgeon. Depending on when your surgery was and the type of procedure done it may or may not be indicated. Talk to your surgeon for a clearer picture.
Yes. But you need to talk to your surgeon about this continued pain.
See details. You should address this issue with the orthopedist who performed the surgery. That doctor knows the specifics of the injury and the surgery performed while I do not.