Brief Answer:
It is called coccydynia

Detailed Answer:
Hello,
I have studied your case. Pain at tail bone is called Coccydynia. In this condition there is pain on sitting on hard surfaces. .As you have already tried some of the conservative treatment so I have following suggestions for you.
1. Injection of steroid can be given in tail bone by doctor under x ray guidance. It is very effective and may cure this problem.
2.Sitting in hot water tub (Sitz Bath) helps.
3. Some patients who are not responding to these treatment can be benefited from minor surgery where all crooked tail bone is excised.
Along with above mentioned treatment you should continue avoiding sitting for long time, constipation. You should continue using ring like cushion for sitting.
I hope this answer will be helpful for you. Let me know if there is any other followup questions.
thanks

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