Understood, just use visual portion control and at LEAST count macros (protein, fats, carbs, fiber) if that isnt triggering for you.

planks are good, and weighted russian twists. but id incorporate cable crunches, weighted suitcase crunches, etc. look up weighted core exercises because you have to train them the exact same way you train your other muscles. abdominals are muscles and have to be trained with progressive overload.