Your supervisor is right and wrong.

You cannot be forced to work in violation of your doctor's clear restriction. However if you cannot perform your normal job from home or in some other manner other than face-to-face interaction with others, then the employer is allowed to send you home on unpaid leave until your doctor changes your restrictions. Therefore the key here is whether you can perform the normal essential functions of your job in some manner that does not cause you to violate your doctor's restrictions.

From a practical point of view, you probably need to insist on not working in violation of the restrictions. If you are then sent home when it was possible to reasonably accommodate you, your only real option is to file a lawsuit to seek the money you will lose as a result of the employer's decision. At that point it would be wise for you to locate and consult with an experienced employment law attorney as soon as possible to explore your facts and determine your options. I would suggest you look either on this site in the Find a Lawyer section, or go to www.cela.org, the home page for the California Employment Lawyers Association, an organization whose members are dedicated to the representation of employees against their employers.

Most employment attorneys who practice this area of law offer a free or low cost consultation in the beginning and then, if the matter has merit and value, will usually agree to work on a contingency basis, meaning you can hire an attorney without paying any money until the matter results in a positive outcome for you. Many advance all the costs of the litigation as well. Do not let fear of fees and costs keep you from finding a good attorney.

Good luck to you.