mummy - do you have SHOOTING pains in your breasts AFTER a feed ? If so, that is a sure sign of thrush. I agree the lump is probably a blister. Sorry, I am not a doctor, but know quite alot about thrush as my DS and I had it when he was about 5 months old and I have read almost everything available on the web about it !!
The answer to should you stop BF is "no". As you know the best possible cure for any illness is BF. Don't give up at 10 months !! I know it is painful, but with proper medication and a different latch you will get over it.
If your GP or BF Counsellor confirms that it is thrush, I found the best remedy to be Daktarin Oral Gel for the baby and Canestan cream for your nipples. You can get Daktarin in a tube at any chemist, no need for a prescription. I think you need a prescription for Canestan.
Do not bother with "Nystan" which is what is commonly prescribed by GP's. It is full of sugar and only perpetuates the problem as thrush thrives on sugar !!
You MUST treat both of you simultaneously as otherwise you will just pass it back and forth. I would also suggest a light distilled vinager solution after each feed (1 tablespoon vinager to 9 tablespoons water), but that may be too painful for you with the blisters. Thrush dies in an acidic environment.
I did all of the above for 6 weeks and it worked ! You have to keep going for at least a couple of weeks after symptoms get better.
One day he did not feed at all for an entire 24 hours which is when I started to panic. I think the thrush caused a sore mouth/throat, although he never had any visible sign of thrush (i.e no white patches, etc.). It may be that your baby is having the same problem, plus the teething will cause sore gums. Babies often BF more when they are teething. Mine does !!
Good luck !