Hello sir, it's always advisable to go for root canal treatment it better you do it as soon as possible
if you postponed, the teeth will get even worse and you will end up removing the teeth.
Ignoring with pain killer is not a solution after a week your going to develop it again.
And there are chances to spread the infection or decay to the other normal teeth by contaminating your saliva.
Next Steps
Brush twice and save the other teeth from decay/infection.
Health Tips
Go to your dentist as soon as possible for the root canal treatment don't ignore it.