Hi,
This is really not an area I'm familiar with so I'm just throwing some thoughts out there. Firstly your tonsils are located each side of the back of your throat, for years I used to think they were on the end of that dangly bit - gee thanks loony toons for that idea lol. This is probably the site of the hole you describe as your adenoids are much higher up your throat at the back of your nose, almost above the roof of your mouth and often removed at the same time as tonsils. Both tonsils and adenoids are part of your lympatic system. Did you not get follow up appointments to be checked after surgery? If not I would return to your DR, or ENT specialist, even give them a call and ask them why this is happening. The throat can take longer to heal because it's always wet. In the meantime I would try to keep it as clean as you can, I'm a fan of cooled kettle water with some table salt (you can blame my mother and her old wives tales for that) if your not keen some sort of mouthwash, especially after eating as should anything get in there it's likely to get infected. It may be an idea also to try and limit as much of your food to liquid and soft type foods until someone has a look at this. If your weight starts to suffer you can top up with some meal drinks for people who are either unable to gain weight or unable to eat solid foods. They can be a bit expensive but contain all the vitamins and nutrients of a proper meal and a high amount of calories. I'm really sorry I'm not more help with your situation.