I agree-the first thing you need to do is to learn how to make the foods you DO like healthier-if you like hamburger-get extra lean instead of regular-it has a lot less fat. Bake or grill pork chops instead of flour dipping them and frying. Bake your potatoes instead of frying them.
The second thing you need to do is to TRY NEW FOODS. Make a goal to try one new thing each week. A lot of picky eaters "assume" they don't like something, or won't like something-and they haven't even tried it yet.

I am not saying to try something way out of your comfort zone at first-like tofu or anything, but start small.
Take apples, for instance. Most everyone has had red delicious or yellow delicious apples in their lifetime. They are "average" apples. Try a new variety of apples instead-gala and empire have a wonderful, slightly different flavor. The empire apples are a little more tart and crisper than red delicious, for instance. If you are afraid of trying something new-then go for something a little familiar to you-but a "little different", like this example.
People who are used to whole milk for instance, usually cannot switch to skim/nonfat milk without a big "UGH!" The key is to switch over slowly to 2% for a while, then 1% for a while, and once they are used to that they can go to skim without a problem. It is just slowly getting used to going from full-fat to nonfat.
You can learn to enjoy new foods if you go slowly and try things a little at a time. Going from pizza and burgers to enjoying grilled chicken and fresh fruit at meals doesn't happen overnight.
