Take this job and shove it!

Just a rant.  I am so angry with this job!  I turned in a doctor's note and bent over backwards so that  I would not have to endure all the walking involved with teaching the computer class here.  So, now the evil witches whom I work with have decided they don't want to do all that walking either. Now the supervisor wrote up a schedule that each of us has a day where we have to get up and walk and get the door.  I am included in that schedule as well.   So, if I am using my cane or walker or wheelchair on those days in which I am scheduled to answer the door, what do I do?  I thought my doctor's note would cover that issue.  It specifically states that "the walking involved" is too much.   I feel I will have to discuss this with my supervisor.  I just want to calm down and get some feedback from others before I do.  I am so sick of the things the other girls do to "get even" with me.  They act like I am getting special treatment so they don't want to do their jobs either.  I feel like they think my disability is all a fake.