Uncontrollable hunger

My beautiful boy is 15weeks old this week- the past 4 weeks I can’t get enough food, I’m hungry all the time! I don’t drink as much water as I should and eating rubbish, I’m concerned about gaining weight and stretching out my tummy (3 yrs post gastric surgery). Does this hunger go soon? I desperately need to reset tummy and my diet but can’t do what I need to due to breast feeding .