I’d try replacing the chocolate for something else. So if you’re hungry, instead of a chocolate bar, swap it for something else like an apple, some piece of fruit or veg. Also, if possible cook your own meals. Learning to cook fresh meals makes you excited to eat it (at least for me, I get way more excited when I make my own curry than when I use a crappy microwave one) there are those weekly or monthly kit things that give you the ingredients for meal recipes, maybe try them? I wouldn’t say go cold turkey, maybe use chocolate and stuff as a reward. So end if each week, treat yourself to a chocolate for being healthy the rest of the week. Try and surround yourself with healthier options, since the more unhealthy stuff you see, the more tempted you are to indulge yourself.
Hope these tips help, this is just what I can think of on the top of my head