Although your condition is not very common, surgery is likely your best option. If the nerve pressure isn't relieved soon, it is possible that muscles controlled by the nerve will continue to wither and weaken. Left untreated, the damage could become permanent.
Of the few cases like yours that have been recorded, two patients who went on to have surgery got better quickly. One had full return of hand strength and function in less than three months following her surgery. The second person had greater complications before surgery but still ended up having a full recovery by six months.