I think the best way is to start small. Change small things in your diet. For example, if you like chocolate, switch to dark chocolate. If you like biscuits and crisps switch to those healthy alternatives. Homemade popcorn apparently is a very healthy snack. Or even just healthier crisps (e.g. Twiglets I believe are better than average).
Drinking more water will suppress hunger. So maybe worth doing that. Will also make you feel better, and tends to relax you. Eating fruit, especially stuff like apples can fight fatness.
Just try and pinpoint the foods you love, and make an effort to eat healthier versions of them. And of course don't buy/keep in the house stuff that's bad for you.
I think a lot of times people stuff it down you're throat that you need to eat less. But that's hard to do, if you're body is hungry, it is hungry, and if you try to ignore it, you feel bad/depressed. Think the best thing to do is fill your house up with healthy snacks (do a bit of looking around, find out the stuff that you really like), eat fruit, drink lots of water and eat to your heart's content (as long as it's healthy). Just be happy doing that. Even if you don't lose weight, chances are you'll feel better.
While I'm sure you'll look better thin, being thin isn't just for looks. You'll be fitter, better able to play sports. And indeed switching to a healthier life style and having a healthy body will feel good, and you'll feel healthier both in body and in mind.
It does sound to me that you are saying "it won't make a difference" because you're trying to justify not losing weight, and eating food that's bad for you. It's much easier to give in, hard to persevere. Which is normal. Just having all those unhealthy foods not around you will help.