How do I eat healthy on a budget uk?

I really don't want to eat sweets or chocolates anymore. I need cut back on that so that I don't have it in the house. And reduce my cravings and be healthier. Only concern is the cost. I'm hoping that by doing this I reduce my cravings and there for don't over spend on food I do not need. Is this a good idea? I'm open to batch cooking and saving the rest in a freezer. I'm trying to also cut back on carbs.