Tooth pain because of a broken tooth and exposed root canal ?

Tooth pain, RCT?: You will have to see a dentist in order to determine whether or not that tooth can be saved and if so, what needs to be done. You may require root canal therapy which can be performed by your dentist if he\she can, or referred to an endodontist if not. Severe pain in a tooth does not always require rct. The sooner you go, the sooner you'll know.

Yes!: It sounds like you need to see your dentist asap. If you have had a root canal previously done on that tooth there may be a crack in the tooth.

The simple solution: If you have a severe toothache, seek immediate help from your dentist before the problem becomes worse and more complicated. Remember, toothache pain will not go away on its own.

Toothache : That can happen...tooth sensitivIty can also occur from exposed dentin which can easily be fixed with a filling

Abscess ?: It's very possible. Call a dentist ASAP for an evaluation appointment. This won't get better on its own.

No self help: Need to see a dentist asap. No way to try and DIY. Go soon since the pain and/or potential infection could get worse.

Yes: Yes, those can cause tooth pain. See DDS ASAP.

Retreat root canal: could be a fracture of the tooth/root or the canal has been reinfected from the top down (takes less than 30 days of exposure).