No need to go on a special diet, just try to exchange some of the unhealthy options with more healthy ones and there you go. It is way better to stick to small changes than to overthrow your diet every two weeks.
As for salads: lettuce is not for everybody. Try a oven roasted apple, beetroot and carrot salad with roasted pumpkin seeds instead. Yum!
Even cooked vegetables are good for you and have very few calories, unless you top them sauces, cheese, etc.
You don't have to stick with a single diet program. If you opt for high protein, whole grains, low/no fat dairy and lots of veggies, you should be fine. Watch portion sizes.