OMG, how awful for you and your daughter. I don't really have a lot of suggestions except maybe check a book out of the library about going to the dentist. We have the Berenstain Bears dentist book and have read it a lot and it really helped dd not be scared. I also think you should see another dentist. I'd be very concerned about a dentist who is suggesting crowns for a 2 yo. My dd had a cavity on her last visit and the dentist said that they would just keep an eye on it and as long as it's not causing any problems they're just going to leave it alone since it's a baby tooth. I think you'll feel better if you get a second opinion, even if you have to pay for it out of pocket.
((HUGS)) to you and your dd.
((HUGS)) to you and your dd.