Make sure that your dentist did not use a material commonly known as Sargenti Paste, aka Sargenti Cement, N2, RC2B, RC2W. It contains formaldehyde and can cause all kinds of problems after a root canal especially if the material was extruded out the bottom of the tooth. Problems can be immediate or even months to years after the root canal. It is unlikely that an endodontist would use it because the American Association of Endodontists (approved by the ADA) is strongly against it (see link below). If a general dentist did the root canal, get a copy of your records (if you can) and go to an endo. Don't expect the dentist to be honest if they used this stuff. These Sargenti using dentists admit to not telling the patient because "they don't understand formaldehyde". BS. They've been trying for 30 years to get this approved at the FDA and haven't been for a variety of reasons, the least of which is that they have no scientific data to debunk the decades of research and patient problems. They rely on self-serving testimonials from the DENTSTS (not the patients) that use it and do not tell their patients that what they are using is widely considered below the standard of care. Every root canal where sargenti paste is used should be followed up with a good malpractice suit. Most dentists will settle out of court because they don't want the publicity and for the rest of their patients to find out. They don't tell you because they know its not FDA approved, never has been, never will be.
Don't assume that your dentist who you've gone to for decades wouldn't use it on you. The worst case of it (that made the news) was a lady in Florida who had her dentist, a family friend, use it on her.
Don't believe anything you read that comes out of the American Endodontic Society. this is the cheerleading group for the use of this stuff and no one with a brain in the dental industry supports or believes anything they say.
http://www.tupeloendo.com/pdfs/AAE-Guidlines/AAE-Position-Statmement-Paraformaldehyde-Filling-Materials.pdf
The new symptoms you describe do not sound related to a root canal or subsequent complication. Tingling is the normal sign of healing, and its highly unlikely your nerve would start healing years later. However, checking with your neurologist is a good idea.