There are so many good posts here! We utilize a lot of the tips here, but TBH, fast food isn't a temptation. For me, it wasn't a financial quandary, it was taste and nutrition. This would be back when hamburgers were 39 cents and cheeseburgers were 49 cents. This was probably 20 - 25 years ago.
Fast food was A LOT more unhealthy back when I decided it wasn't for me (fries cooked in lard, fewer regulations... the Reagan years). Fast food was actually really inexpensive... I could eat a meal for under a dollar. Then I really got into nutrition because I was getting into competitive cycling and for performance, it was about fueling the body, not just eating. It's amazing the difference you feel when you stop eating processed food!
Ultimately, I think to break the habit, you have to have a reason that *not* eating it is more important to you than eating it. Often knowledge is power and once it's known how these foods are made (inhumane practices), what's in them (food by-products and fillers), what they are treated with (ammonia, for example), and how they affect your body (slowly kill you), that is the catalyst. The books and movies recommended are good for that. The guy who did "Supersize Me" was actually close to liver failure after eating only McDonald's for a month. That's just SCARY!
From a financial perspective, have you ever kept all the receipts and calculated exactly how much you're spending? You might find that the money could be spent to actually hire a mother's helper or someone to run your errands to save you time to be spent in the kitchen.
You have 5 people in your family, assuming from your signature and that you have a significant other. I'm not sure what prices are at fast food, but based on some of the other posters, I'd assume that it's about $4/person on average. Pizza, I'm sure is more. We get a pizza from a local gourmet pizza place and that's $25 for 4 of us.
So, if you're eating fast food just a few times a week and getting pizza once, you're probably spending at least $300/month. Probably more! For that money, you could hire someone to help out just to get you started and, you'd still save money in the long run. Once you're in the groove of prepping ahead, you will be able to do it in less time. I agree that it's a process and will take a while to get used to it.
Actually, for that much per month, you could have a personal chef to make a meal for you, in your home, twice a week! I considered doing this a few years ago and when I was researching it, the going rate was about $300 for 8 full meals (cooked in your home)... all fresh ingredients, nothing processed. It was even less for refrigerated meals that you put in the oven yourself... probably not much more than fast food.
Good luck on kicking the habit!