There are many reasons people hate photos of themselves.
One of them is that we look much larger than we expected.
Don't be so hard on yourself!
It MIGHT be because of an optical illusion in the camera.
Our cell phones are wide angle lenses which cause distortion or stretching at the sides of the image.
Things look larger in these areas!
If you are taking a photo of yourself, back up a little and come up with the angle of your camera and this optical illusion is diminished!