That's inconsiderate, I'm sorry to hear that happened to you. They could have at least called you and say that your appointment is postponed; and would you like to reschedule. I don't know why doctors feel like they are entitled to treat patients that way. If you did that to them, they would give you a lecture on how inconsiderate you are and charge you for no appearance (in person, online, or phone).

That C.A.L.M. sounds good to me, but I don't know if it is. From some articles I've read (and I may be wrong about this; forgive me if I am) about loneliness in the UK, it sounds like there's more help there than in the US.