Need some help pls

I'm 23 turning 24, 5'2" and 260lbs. I'm try my best to lose weight, but my addiction to junk food and overly processed food is getting in the way.

I know that whole "eat everything in moderation" and "no restrictions", but it hasn't worked for me. Whenever I get something sweet I have to eat THE ENTIRE THING. It's so annoying because I do want to eat a cupcake without eating the rest of them. Or to eat a little bit of chips instead of the whole bag.

I'm trying to be in a calorie deficit and exercise regularly and make the necessary life style changes, but this truly has been beating me across the head.

I'm trying to eat at a 500 calorie deficit and getting at least 6k steps everyday with some yoga every night. But I can't even stick with that because I've been eating so much.

I just need some help with this please!