Tooth Ache. The root canal. please help!

3 months back i had my root canal in the 2nd molar.At that time in the x-ray the doctor found that the 3rd molar is tilted and was pushing the front tooth.The doctor told me that may be in future when the 3rd molar will errupt it will cause pain.Right now i have a very severe pain in my tooth the crown is so sensitive that even when the upper teeth are touching it,causing a very severe pain that i can't bare.Now i talked to my old doctor and he suggested me to take the antibiotics that he reffered me at the time of root canal.I took the tablets in the afternoon as it was paining like hell.But again the pain started.I think only for the time after taking the pain killer it is giving some relief but after 4-5 hours it agian started paining.What should i do now. I'm sending the picture of the x-ray i took before the root canal. Please help