I’m going out on a limb here…swollen lymph nodes are usually a sign that your body is fighting something. A fever is often present when there is a systemic infection because a raised body temperature helps the body to kill off the virus or bacteria causing the problem. In some cases, a lowered body temperature occurs instead of a fever & in others, there is no change in body temp. It may be that your body is working so hard to recover from surgery that it’s not doing a good job of fighting whatever is causing your lymph glands to swell & hurt. Either that, or whatever is causing the lymph gland swelling is something that your body is not fully acknowledging as an “invader” so it’s not responding full force to try to eradicate it.
Since I’m not a doctor, I could be way off base, but whatever the cause, I hope that w/ the collaboration between your surgeon & your doctor, you get a diagnosis soon & treatment to help your body start moving toward full recovery. A visit to an immunologist as Jules suggested is not a bad idea either.
I’m praying for you!