Are you American?
If so, you need to apply for a temporary handicapped permit thru your own state.
Each state is a little different in terms of which department issues them - often the Department of Motor Vehicles.
Exact forms that are used varies a bit state by state (although the information is usually pretty much the same). Your physician would need to fill out the form to certify your disability - they may have the forms or should be able to find the forms online.