Is there anything I can do to get the dizzyness to go away?

I ran into a pole and hurt my head at work yesterday. I told my boss and he just laughed so nothing was done and I had to work. I have to go into work soon and work a long day. we have spy shoppers and if we mess up, we lose our job. In other words I have to be perfect and ask everyone the same questions over and over again. This is hard enough to do everyday being that the store gets very busy. I am very dizzy today though and have a headache. I can't call in because we don't have any extra coverage for my department and any call in at my jobs counts towards getting fired if you get so many, even for illness. Is there anything I can take or do to feel bettter? I have taken advil and it isn't working and i can't go to a doctor. I will be dealing with some very bitchy customers as usual on monday and it isn't going to be easy being cheerful and pushy in sales when I feel bad. I won't be able to sit down at any time because I work in customer service.
Don't play with this! Dizziness after a Head Injury could be a sign of a mild concussion. Tell your employer to fill out an incident report on this matter. Insist that this be done. They can not fire you for this request, unless you were doing something you were'nt supposed to be doing at the time. In many instances you only have a certain amount of time to file a workman's comp report. See a Doctor that your company approves of soon.