Hi, You are getting pain because tooth is infected, since Root canal treatment is incomplete. If you have mild, throbbing pain once a while, take pain killer. Once, Covid settles down, you should visit a dentist. But if you severe pain, it comes under Emergency treatment, you should see a dentist. Once Dr.takes a X ray, it will give you a clear picture.
Next Steps
As Suggested above
Health Tips
If pain is severe, unbearable, then see a dentist for Root canal treatment. If you have tolerable, mild pain see a dentist after Covid Lock down. With This approach you will Take care of yourself and your dentist, as responsible Citizen. Regards.