Somebody at my work had something similar but she's 50. She was diagnosed with Bells Palsy. Half her face went numb/paralyzed. It took several months and a lot of medication for it to go away.
I just checked with her and she also had the cold sores in her mouth. So you will want to go see your doctor.
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Sharp pain in the side of face could be due to injury to a nerve or pinched nerve, an infection or a trauma. Hence it could be Trigeminal neuralgia, abscess in tooth, exposed root canal, internal ear infection, maxillary sinusitis, TMJ, migraine, shingles or fibromyalgia localized to face. Since you have TMJ like pain and cold sores, possibility of shingles should be looked into.
Since I cannot examine you and know other related conditions you may be having, nor is a detailed history possible on net, I have listed the various possibilities that should be looked into. Please consult your PCP to run tests and examination to clinch a diagnosis.