I've never had parents threaten to chop off a body part but my brother and brother will occasionally gang up on me and tell me I need to live in a facility. I find it strange how NTs are quick to blame 'us' for the slightest of damages yet can steamroller over our emotions. Can you differentiate whether your mother is making a literal threat or just speaking NT for "If you wouldn't mind to do the dishes that would be a great help"? Taking things literal is a huge Aspie trait and I've walked into that myself. My family look to me when they need to spell or find a word or have a music question, then in the next breath can slam me for some kind of ingratitude. You might try asking your mom if she would seriously cut off your hand, and if so, ask how you would be able to wash dishes with a missing hand. (If you don't eat your meat, you can't have any pudding, how can you have any pudding if you don't eat your meat?) or something like that