hello and welcome to HCM forum ,
i am glad you wrote in, according to the dental history provided by you it seems that the tooth still has infection due to which you have been in pain, i assume there is no swelling around the tooth, but if there is then kindly revisit your dentist
and get the crown removed.
i am not sure about the numbness
in the extremities,but its not due to the tooth for sure.
for this you will have to consult a neurologist
swollen glands is something which needs to be checked thoroughly, i would have appreciated if you would have attached an x-ray of your RCT treated tooth.
on the whole, crown is nothing to do with pain , it is the infection which has not resolved yet,
therefore kindly visit a specialist(endodontist) soon.
i wish you good health,