While it may be difficult to admit, there are times where you don't exactly love yourself. It is important to remember that it happens to all of us on occasion, which may be even harder to believe.
All humans are bestowed with an innate desire to be "perfect." This is a very dangerous flaw that has been ingrained in us. It is vital to remember that the concept of "perfect" is subjective. Not only this but that achieving "perfection" is impossible. Once you think you've achieved the perfect body or hair or what have you, you will absolutely find something else about yourself that you don't like and then want to change. When you don't embrace what you naturally have, you will always be disappointed in yourself.
This problem with seeking perfection that we have directly stems from comparison. The very moment you start comparing yourself to others around you is when you become more critical. One person's strength can be seen as your weakness but that leads to a narrowed view of your strengths. Two people's great qualities aren't going to be the same. Neither are their respective weak qualities. These qualities can determine what you're passionate about or what you can contribute to society. People need to contribute different things for a more well-rounded humanity.
Accept what you can't change, and strive to better what you can change.