I had a similar pain. I had never had a root canal before and just had some "twinges" and pain in my ear on and off. I went to my dentist to have it checked out and everthing looked fine (I even looked back at the xrays with him some months later).
Well, waiting to go to the endo and trying to save some bucks wasn't worth it. I ended up in the hospital for 10 days in IV antibiotics and morphine. I had a root canal (and crown) about a month after I was discharged. It took me months to recover fully. Puzzled everyone - dentist, ENT, family Dr., etc. Strange for an infection to settle in like that, but it can happen. I was really scared at first, they thought I may have a tumor in a salivary gland which could have been malignant. I even got placed in the Oncology wing of the hospital.
Needless to say, I'd vote to have the root canal.
I hope you feel better soon!