Joseph F. DelPrete, DMD

You need to go back to the surgeon to evaluate the bleeding.  Are you taking any medications that can decrease clotting?  You should not be bleeding 2 days after the surgery

You should have a dentist look at it and see if it is a cavity or a stain.  without a picture or radiograph it is hard to give you a good opinion.

You should not need to be in pain for two weeks.  If the endodontist cannot see you for two weeks, ask if the dentist can do a pulpotomy.  Or find another endodontist

You need to see a dentist. If not treated you can end up with a severe infection.  There is no home remedy

It is possible that decay can get under an existing bonding.
but it is also possible a nerve could be going bad .
i suggest you have it looked at by a dentist