Hello,
Your symptoms are suggestive of early satiety (feeling of fullness even before completion of meals). Causes for such symptoms are gastritis,
gastroparesis(delayed gastric emptying,a disorder in which the stomach takes too long to empty its contents),gastric outlet obstruction, heartburns due to acid reflux(GERD),irritable bowel syndrome, diabetes, hyperthyroidism ,cushing’s disease and rarely GI especially stomach tumors.
Try raising the head of your bed about four inches with blocks.