My left ear hurts along with the left side of my face being swollen and sore. It is also causing me to have a headache. What could be wrong?

TMD or Parotid. If your hearing has not changed, it is unlikely that your ear is causing your discomfort. The two diagnoses that come to mind are masticatory muscle spasm or true jaw joint disease or inflammation of the parotid gland, a gland in front of your ear which secretes thin fluid into your mouth. The headache is probably referred pain. Consult an ENT doc for appropriate diagnosis.