Unexplained Constant Hunger

I'm a 28 year old male, and for the past two years i had this insatiable hunger. At first i ignored it, but after time it caused me to gain a lot of weight. Even if i eat huge amount of food, some days exceeding 5000 calories, i still feel hungry, as if i havent eaten anything. Also, i have hard stool very often, even though i regularly eat soups and other liquid food. I have no cases of diabetes in my family, and i didnt notice any increase in the number of times i urinate per day (since that is one of the symptoms for diabetes). Thank you in advance for any advice you might have.