Firstly root canal treatment actually is saving your tooth. The nerve is exposed means you will be in tremendous pain. Use Colgate painout for immediate relief but also visit a dentist at the earliest or extraction would be the only left over option.
Also do tell if you have a swelling or pus.
Next Steps
Visit an endodontist and start up on antibiotics and painkillers asap
Health Tips
don't let food get lodged there