I'm not familiar enough with SMART to comment on completing the exercise, but I think you came up with great alternatives.
I really hope that pumping my brain full of dopamine hasn't introduced me to a high that is irreplaceable!
I'm gonna say no that you haven't messed up your brain for good. I have heard people say they struggled to match that high, sure, but it can be done.
It's weird how much the mind can flip flop in such a short period of time. Now if I can only keep it flopped into this perspective when the next craving hits...
It is weird, and for me, mastering the mind and managing the super intense cravings was an amazing feeling.
Keep it up GW, you're doing great!