OK, if you are trying for realistic portrait your proportions are off. Do you know the basic proportions of the human head? (no insult, just wondering). The eyes should be in the middle, half way between the top of the head and the chin.
A positive, the eye itself looks amazing! And Oil pastels like any medium requires practice. You might do better doing pencil first to perfect your portraiture before using stuff like pastels which are more of a pain and can be tricky.
Hope this helps some. You have a good start, practice will make all the difference as will knowing and following the correct proportions.