Sentimental value is still value and therefore they both should've respected that and backed the hell off. They both should've taken your feelings into account verses their 'logic'. Why did it need to be sold in the first place?

I'm sorry you don't seem to have anyone to turn to. A therapist is a good idea, if anything to debrief, but I'd understand apprehension. Either way, I'm here and listening. In no relationship should anyone ever think they have the right to make you feel small. Ever. It's not right, not healthy and just plain ignorant.

Have you told your husband how it made you feel? It might push a comfort boundary but maybe it'd be worth exploring.