For this to be occurring to you for over a year now tells me yes, there is something definitely wrong, but what it is I'm not sure. I think anytime you have pain that lasts more than a few weeks and doesn't go away on it's own needs to be addressed. I think it would be wise to see your doctor again, or, if you feel like your concerns were easily dismissed with the ENT, you might try a different doctor. You might suggest an ultrasound or CAT scan.
I'm assuming the swelling is from lymph nodes in your neck. Since this occurred right after your surgery, it seems directly related to it and probably not something serious like cancer. Something else that might help ease your mind is that swollen lymph nodes related to cancer are not usually painful.
Sometimes you have to be pretty persistent with doctors when trying to find a diagnosis. This may involve suggesting different tests, seeing your doctor multiple times or even switching doctors. It's obvious that something is going on, and I hope you find some answers soon.