Oh the infamous Zebra cakes, so deadly. I have been there (although my particular little debbie vice was with the honey buns.)
Someone posted that you have a 'rather unhealthy relationship with food' and that you should seek counseling. While this comment is well intentioned, it just doesn't sit right with me at all. It implies (at least in my opinion) that there is something wrong with you, that you are at fault. It's not that you have a 'rather unhealthy relationship with food', it's that you're addicted to processed food and (more importantly) sugar. You were probably raised in a society (I'm assuming the US) where it's food system has been completely and utterly co-opted by the (greedy, insidious) processed food and sugar industry (a trillion dollar industry btw.) Like millions of other Americans, you are addicted to processed sugar. This is not your fault. Do not feel ashamed. Please remember that. Processed food/sugar addiction is a systemic problem of epic portions, And as others are saying, take this one day at a time. If you mess up one day, there's always tomorrow. Your always just a few weeks (really days) away from cleansing yourself away from sugar.
Can I as you a question? What do you drink throughout the day? Do you have at least one sugary type beverage daily? (diet drinks included?) If so, cut them out immediately. Cold, refreshing water is the way to go here, all the time. If you especially crave the carbonation from soda/diet soda, you will find that seltzer/sparkling water is a fantastic way to supplement this craving. If you are worried about your weight, completely cutting out all sugary type drinks from your diet will contribute to rapid, almost effortless weight loss. This is essentially fool proof. If you can manage to stay away from the little debbie food pastry type stuff, and you stick to a rigid paleo type diet, I can almost guarantee you will see a transformation in yourself in less than a month.
Now, about those (processed food/sugar) cravings. This is where it get's difficult, because you are surely going to have them. Just like supplementing seltzer for sugar sodas, you are going to have to find a whole food substitution to off set those cravings. Fruit (even especially naturally sugary fruits like oranges and grapes) are your friends here (as long as you eat them in moderation.) Believe it or not dark chocolate (70% cocoa or higher) is fine alternative to the normal (absurdly sugary) chocolate candy bars. There is absolutely nothing wrong with slicing up a delicious apple (or even better, fresh blueberries) and drizzling some melted dark chocolate on top to eat as a "sweet" desert. These are just a couple examples out of hundreds food items you could be eating to defend against the sugar cravings. I'm sure any solid paleo cook book / website will have recipes upon recipes of completely acceptable 'sweet' options.
Also, here is a morning smoothie recipe that helped me out tremendously with sugar cravings. I made and drank this smoothie almost every day for 6 months, and I still make some variation of it 5-6 times a week. It's delicious, extremely high in nutrients and good fats, and most importantly void of dairy and processed sugar. Feel free to make any 'reasonable' substitutions as you see fit.
Morning Protein berry-nut Smoothie:
1/2-1 cup (your preference) of fresh or frozen blueberries 1/4 cup fresh or frozen strawberries 1 banana, chopped 1-2 tablespoon (your preference) of almond butter 1-2 tablespoon of coconut oil 1 tablespoon of soaked chia seeds (optional, but highly recommended) 1 tablespoon of raw pumpkin seeds (optional, but highly recommended) 4-5 walnuts (optional, but highly recommended) 4-5 ice cubes 1 cup unsweetened almond milk or coconut milk 1/4 cup of water
*Combine ingredients into blender, blend for 1-2 minutes. * If you like more of a "liquidy" smoothie, just use more coconut/almond milk or water.
Keep the faith, and keep commenting here if you have problems in the future.