I think it's a great idea not to try to change too much at once.

The only thing I might suggest doing differently is to substitute something satisfying for the crackers, rather than trying to limit your consumption. Those crackers are loaded with sugar and salt and pretty much guaranteed to make you ravenous. How about a handful of nuts or something else high protein/low sugar for your snacks, INSTEAD of the crackers? I'm getting the feeling that your craving for butter is your body trying to balance all the sugary carbs that you put the butter onto.