Thanks for sharing your concern.
Generally root canal treatment
is done under the effect of local anesthetic
,this is done by injecting anesthetic agent in close proximity to the nerve
trunk ,so that it prevents conduction of any pain impulses in that area.
Therefore, in this case you might experience pressure on your teeth but no pain.
Root canal is done in three to four sittings, and each sitting takes around 20 to 25 minutes ,based upon stages of treatment.
Now a days single sitting root canal treatment is also done with painless technique.I would suggest you to go for that.
you will have to look for an endodontist to get this treatment done,painlessly and successfully.
i would also suggest please avoid self medication
in any case.
self increase or decrease in drug dosage might put you in trouble,therefore consult your physician before taking it.
Hope it helps.