I'm sorry you feel so awful still. We use grapefruit seed extract syrup, just a few drops, in a small amount of clean water, just tap temp, and gargle gently as far back as you can. The stuff is bitter as hell, but we like the effect. Then we stick a Thayer's Slippery Elm tablet in a cheek to dissolve slowly and coat the throat - cherry is our fave flavor by far.
For a sore throat caused by post-nasal drip, I use a Sudafed... I hate sore throats with a passion and am not above killing that variety with drugs.
If this lasts too much longer, or gets worse, I would go see the doc - sometimes strep is the cause.
Hope you feel better soon!