Your doctor has no evidence to support his claim that your concussion has healed. Obviously a WC doctor. They rarely have a good understanding of concussions.

Be very careful if you are going to be on the road. It would be better if you can work in the yard where the public are not at risk. Loading salt and sand or whatever there is to do in the yard would be a good start. I'd hate to see you in a 15 ton truck driving down the road and turn your head and get dizzy.

Stay safe.

My best to you.