How do you get over decompression sickness?

Usually from diving. It is the body's response to reduction of pressure without equilibration. Usually associated with too rapid ascent from depth, it is also called caisson's disease because of the air pressure necessary to keep water excluded in contruction (e.g., deep bridge abuttments).
The short answer. Is re-compression and gradual decompression. If you are where there is a hyperbaric chamber in a hospital i would recommend you consult them soon. University of maryland has single and i believe multiple place hyperbaric chambers.
Recompression. Decompression sickness is treated w 02 initially and then recompressurization as soon as possible. Hyperbaric chambers are used for this purpose or it can be done in water. 24 hour dan emergency hotline - (919) 684-9111.