You will need an RCT+cap or an extraction both of which will sort out your pain as well as the the issue of the sharp edge.

Dear Practo User, A thorough clinical examination is required before a final treatment plan is made. With the description you provided, it looks like you would be needing a root canal treatment or extraction based on the condition of remaining tooth. Kindly visit a dental surgeon nearby. Regards Dr Ankit Jain Arham Dental Care, Delhi

This problem has occurred because you neglected the symptoms for a very long time..... clinical examination and x-ray will be required to ascertain the present condition of the tooth, whether it can be saved or not..... if possible, do try to save the tooth by undergoing root canal treatment followed by a cap...... otherwise extraction is always an option as the last resort.... Regards....

Hello..As you complained of pain, decay might have progressed to vital tissue.you may get root canal treatment followed by crown or extraction done after proper clinical examination.sharp edge has to be smoothened as it may lead to ulcer in tongue.kindly visit dentist as soon as possible.

First of all rush to your dentist and get trimmed that sharp part to avoid further injury to your chick/tongue, and these days dental treatments are done with fine instruments with little or no pain (that to done under local anaesthesia) so don't worry about the pain part, later your doctor will guide you about the further treatment depends upon the condition of remaining part of the tooth(root canal,extraction or filling with composites) so get your dental checkup faster asap.

Get the sharp edge  grinded to prevent injury  to tongue also seek a proper advise via clinical examination  and  xary  for the treatment  of the tooth

You can have either your Root canal treatment done followed by ceramic capping or get the tooth extracted. Thanks