Extreme pain in my throat (left side) whenever I swallow anything it feels as though I'm swallowing glass. I know it isn't a sore throat. It only hurts on one side and especially when I swallow liquids.

I . I cannot tell you the cause of your pain. If you look back in your throat, or have someone else do this for you, and there is significant swelling on the the left side of your throat/ left tonsil and it looks like it is dripping pus or contains pus, that could be problematic. If that were the case, you would need to be promptly evaluated to ensure that you did not have a peritonsillar abscess (a painful pus filled inflammation of the tonsil or the nearby tissues in the throat).
Evaluation . Evaluation of this with the special viewing equipment that an ENT has will probably give you the answer that you are looking for.