ishould Get your husband in a receptive mood and gently come round to the subject of the carp. Try to get him to see that all this stuff is an unnecessary burden to him, which he is trying to avoid, as it's mainly out of sight!
He needs freeing from the sad memories, and perhaps the anticipated guilt of getting rid of these things. He will feel much happier when he has finally laid his parents' (stuff) to rest.
Perhaps, he expects to be just carelessly tossing all these sentimental things into trash bags? Explain that it would be a calm, thoughtful, and respectful process. And he can thank everything for the part they played in his and his parents lives. 
If you can get him started, he may find that it is not so scary as he thought.
Greymalkin Yes, Chazzers are CS - Charity Shops. The first Law of Decluttering is: Don't let any non-essentials into your home, by any method! This prevents the situation from getting any worse.
So, if you really need some clothes to fill essential kondo gaps - look in chazzers, mindfully - know what you actually need, and ignore anything else!
Great training for the future! 