as I see it you have two obstacles to overcome in really helping you with your obstacles in avoiding processed foods and a successful fasting programme.
#1. Do not allow yourself any access to processed foods: those you do have in the home........discard them...........put them in the trash. Don't feel tempted to buy any if you are out and about.
#2. The psychological approach to fasting..............in a life-threatening situation where fasting is your only lifeline, then you WILL do it.
On the other hand, if the mental impetus is missing, then you will have to discover one..............surround yourself with literature on fasting and read as much as you can..............it is a very strong motivator in reaching your fasting goals. Your partner should also be inspiring and motivating in this regard. Shut everything else out of your mind, and the chrysalis that is YOU, WILL emerge as a beautiful butterfly to a new and joyous life.
The post-fast plan will also be much more successful if you follow the rules of food combining from the link I gave you; I just cannot emphasize too strongly just how important & vital this is.