Most people who are successful at losing have found they need to do more than "eat healthy." Most track their food in some way--either with a formal program like Weight Watchers, or just something like calorie counting. Without tracking, it's too easy to overeat without knowing it--especially if exercise makes you hungry.
Plus, healthy food is not necessarily weight loss food. Plenty of 3FC members became overweight eating healthy foods...
I know what you mean about being stuck, though--it's really maddening.
Good luck in breaking through it!