I think teenage DN needs help

[PenguinBear]

I personally feel he needs help but would welcome your opinions. (this is about My DN, age 19).

He has a tooth that needs removing. Earliest they can book him is in a few weeks. He was in a lot of pain so went to the dentist who offered to numb it, drill some of the decay and pack with antibacterial stuff . He said no (phobia of needles). She then offered to just put some antibacterial stuff on his gum (which she did).

Afterwards, he got in the car with SIL and was apparently shouting at her and swearing and saying he feels that she and the dentist have violated him and made him do it and SIL has 'massively let him down'.
SIL tells me that she in no way made him do anything and nor did the dentist.
He's now at home door slamming, wishing his family dead for speaking to him and crying and shouting saying he's been violated. When she or anyone else tries to speak to him he is refusing. Apparently no-one understands.

She has rung me very upset and doesn't know what to do. This doesn't seem in ANY way a normal reaction and I think she needs to get him a GP appointment and arrange some sort of help or counselling (he might also be depressed IMO).

[MollyBerry]

Might it be an anesthetic side effect?