Pain/sensitivity in root canal

I had a root canal done about 2 months ago, and ever since i got it done its been incredibly sensitive. The temporary crown was so sensitive that i couldnt even brush it, and now that the permanent one is one, i cant chew, floss, use mouthwash, or hold water in my mouth at all and nothing is helping. It feels like a loose tooth almost and i cant do anything. I went to the endodontist and the first thing he told me was that it cant be that tooth because im not supposed to have nerve endings but i know for a fact its that tooth. he took an xray and he literally just said he has no idea whats wrong and are going to redo the root canal and hope that maybe that will help. Has anyone has this experience? Im so frustrated because i keep paying for dental work i cant afford and i feel like none of the dentists will listen to me.