I know the exact pain you describe. I'm so sorry you're going through this. it's the pits.
Since this is the third day and it has gotten worse I think it's time to go to the doctor. If there is infection you don't want it spreading.
One thing that will help the pain is to hold a piece of rock salt in your mouth. Just keep it in your mouth like you would a peppermint or something. I think the salt kind of cleans things out in addition to having some healing properties. I learned this from my grandmother and have used it for years. Rock salt will be in the baking section with the other salts, usually in a box. Do not use the kind sold for melting the ice outside!
Some people recommend tea and lemon. Tea is helpful but the lemon, being citrus, will make your saliva thicker and increase mucous, which will increase your pain.
Keeping your sinuses clear will help with the throat pain also. I recommend using a netti pot for that, but use whatever works for you. Breathing steam helps also. Sinus drainage will always make a sore throat worse.