Sir your root canal was better done by a dentist before... The situation is your bone loss in between teeth due to improper brushing; May be you brush very vigoursly to remove any food particles but because of that you have done wear n tear of your gums and bones coverings your teeth...
Next Steps
first of all I will suggest you to undergo deep scaling and then just find out in Google or youtube about standard appropriate brushing techniques... Do two times brushing and gargling with mouthwash... you can try ayurvedic toothpaste and ultrasoft toothbrush of Colgate n Oral-B... You continue your antibiotics for 5 days... Take once cap or syrup AtoZ multivitamins for 30 days
Health Tips
Your infections started because of accumulation of food particles and vigourous or hard brushing... and that infection reached to your root canal tooth... Now u have one thing maintain hygiene and then if still pain persists... then we can go for small operations known as apicoectomy in which we go to the end of the root by directly making a way through bone and clear out the infection manually and then we can put graft and stitches but i think no need of extraction of tooth..
Thank you..