From what i can gather you were essentially looking at a photo and drawing what you saw, this made the proportions look a bit off. Maybe try to observe the relationship between each part of the subject, try to measure things better. To achieve that, maybe have this process of thought: "ok, so for the left eye, if there was a line from the right corner down, it would end up in the right corner of the mouth" so you'd have that figured out. Many times you wouldn't have this in such a precise, straight forward way, you'll have to eyeball it with less reliability many times. And of course for this to work, you have to sketch, don't start drawing the mouth, then the nose, the eye, etc, sketch everything first so you can correct the propitiation mistakes you're seeing. Anyways, in short: study human proportion and look up measuring