Hi Jennifer! LTNS
Last time I had a really severe sore throat it turned out to be strep throat. Never had it before & don't know how I got it but there it was. Look in the mirror and use a flashlight to see if you have any white spots back there...if so, get to the doctor asap as you need antibiotics.
For sore throats, decaf tea w/lemon (no sweetener) helped as would the hot water w/lemon. The acid in the lemon seems to help. Another thing that worked well for me was plain Greek yogurt but I don't know if that's allowed on Atkins. There are also sore throat sprays that numb the pain.
Good luck and I hope you feel better soon.