Here's a cure if you can stand it. Take a vitamin E pill and break it open. Squeeze the gel onto a Q-tip and swab over the sore. You can also buy stuff for canker sores over the counter in little vials.
I know for sores in my mouth my mom used to warm up salt water and have us swish it around in our mouths. I don't know if it would work for one in your throat though. You might want to have a doctor look at it.
Gargling with warm water - with plenty of sea salt always works for me! It seems to help it heal a lot quicker...it's a bit yucky...but it works a treat!
I've always found that Pepto -Bismal works better than salt-water. It coats, the Bismuth is anti-bacrerial , & the aspirin in it
treats the pain. I'm sure the only trouble with swallowing is constapation, If you drink enough, but don't try to drink it. Just apply it directly to the Ulcer whenever it bothers you. You can spit out the excess.
A week is a long time in a place that heals as quickly as the mouth. Do this now, call the doctor tomorrow.