Hello.
Let me answer your questions step by step...
According to the symptoms and the X-ray you have sent, its best to get the RCT done as soon as possible. Any form of medications will only buy you time but eventually you will have to undergo the treatment. Your BP and
Diabetes will not play much role in your RCT as you mentioned that they are under control.
If the RCT and cap are done completely then there should not be any issues in the future.
Delaying treatment is not the best option here because the pain is going to get intense and unbearable. Tooth pain can get very bad and will not let you concentrate on you day to day activities.
As to who the best doctors in Noida are, pls send a personal message and I will be able to refer you to an Endodontist (RCT specialist).
Health Tips
Do not eat from that side.
Avoid hot foods from that side.
DO NOT put any form oh hot packs/ hot compression/ zandubalm kind of applications.