In fact, I often dislike myself and find myself plain,slow and ordinary.

事实上，我经常对 自己感到厌烦，觉得自己委琐，平庸，而又迟钝

事实上，我经常讨厌自己，发觉自己很简单，很平凡，很迟钝

实际上， 我总是因为觉得自己平凡而讨厌自己

Please do not use Chinese to understand English, use English instead.

Good luck.