Sir, Get your x-ray done and get checked if there is any root left. Because dull pain occurs when there is any tooth part left inside. If you are busy and not able to  visit dentist, then you can take Tab. Oflox-oz and Tab. Zerodol-SP twice a day for 5 days if you dont have any allergy to it. And do warm saline rinses (Add a pinch of salt in lukewarm water ) for 5 times a day. That would reduce swelling. Rest get it checked by your nearby dentist.