Why are people so discouraging

Im currently down 80lbs from 230->150 and the entire time I had people discouraging me and making fun of me for being strict on what i eat. Im still trying to cut down on some weight (ik im a healthy weight but i want to see my abs, don’t discourage me it is annoying). I am currently in Montana visiting my grandpa before i make my move back home to Ohio and the entire time ive been here he has been criticizing me on what i eat and saying he eats this and is skinny so i need to stop being so bitchy about what i eat, and that i can just get abs by doing situps, he doesnt understand in order for me to see my abs i need to cut down on my body fat percentage. Just the most annoying thing is just the constant discouragement by everyone not by him. I feel like a douche sometimes but i want the body ive dreamed of and it is annoying to have people constantly discourage me on my journey.