How can I treat a sharp stabbing pain in my throat?

You don’t say how long you’ve had this pain but, from my own experience, a sore throat that feels like a stabbing pain when I swallow has always been a strep. It’s a bacterial infection and it is very painful. It can cause serious complications and it doesn’t go away by itself. The only way to get rid of it is to go on antibiotics, like penicillin. This is not an over-the-counter medication. It must be prescribed by a physician (at least in the U.S.). The best thing for you to do, IMO, is to see a doctor ASAP.