A good place to start might be to just try to introduce more vegetables in every meal. Like you, I find it really hard to quit the good stuff cold turkey. Instead, I'm just trying to gradually introduce more good foods into my diet. For example, if I go to a restaurant and order a burger, I'll order a salad instead of fries. It's not the best, and ideally I wouldn't be eating a burger at all, but if I'm going to do it then at least I can compromise with myself and get make it a little bit healthier!