Definitely slow down and back off on doses. Hmmm... a sore on your mouth? Yikes!!! you could be low on friendly microbes. But you're definitely taking in too much lemon juice if your mouth is that sensitive. citric acid s do that to some people. I know people who simply cannot drink any lemon whatsoever, they immediately come out in cankor sores etc. It all depends on your body type.
Getting better is a very tiring business. But we also have to make it to work and all, so do what you have to do in order to stay within your comfort zone. That's why I like enemas so much, they help you feel totally normal as you cleanse your body and take years off your age. :)