Hi Tara!
It's true; diets don't work. But watching what you eat and recording it--either in a journal or on fit day or whatever method you want, does work! So does setting a calorie goal for the day--and sticking with it. The recording keeps you accountable.
I quit smoking eight months ago--and I put on over 50lbs in the first seven months. It shocked me and horrified me, too. But I didn't want to restrict my food--I was using it to "self medicate" my stress. That was not a good thing, of course, but I wanted to be very very sure I wouldn't go back to smoking! Better a chocolate bar than a puff was my thinking. But I went too far. Far, far too far. You are wise to catch yourself now...before you pack on too many pounds.
If you feel, though, that watching what you eat and being mindful of it and so on would in any way trigger you to smoke--then you have my permsission NOT to lose weight, but maybe to maintain until the potential for a trigger is gone.
But, hey, if you're ready to go--fantastic. You've come to the right place!