Hi i had a hornet sting me in a lymph node in my neck. the lymph node is still swollen two days later and i have been feeling constantly thirsty.

Give it time: The toxin produced by hornets (Hymenoptera) will cause local inflammation. The lymph nodes are part of the immune system and I would not be surprised that it would still be enlarged two days after being stung. The thirst may be a side effect of the sting and local allergic reaction, but if no swallowing problems, breathing difficulty or sensation of throat closing it should pass without concern.