I'm shocked you can fold either of the hands you said.
You have more equity than ever to be calling with A,K vs a 7blind shover (A,x,kx,qx,any boardways etc you dominate. Most likely you have him crushed as his most "likely" shoving range is smaller Aces or K,x. Pocket pairs are possible, but still enough equity to call.
As for 12blinds shoving his stack, he's most likely just trying to isolate the 7blind shover with maybe A,5s+ 5'5s+ (more times than ever, as opposed to small pair vs small pair) any broadways etc, again you dominate both either way.
Not sure I can/will ever fold Jacks on the button in a spot like this. For one, you have to realise now, you showed over A,K that you folded, absolutely awful fold (sorry) and he now knows you can fold basically anything that's not Aces with <40blinds..
Of course everytime you raise, he shoves with anything. Ok, you show Jacks and he shows Kings, that's just quite lucky in a sense..not a "good" fold by any means you have to be calling these especially after the information the table now has on you, you can/will be quite easily over run.