Good self-esteem, confidence and faith in yourself are all important things to have. Though they alone are not enough. As humans we are designed for companionship, for interaction with each other. There will always be times when we are alone though, when at that moment for one reason or another you will be by yourself. It is in these moments where we need to be our own best friends.
Of course, this isn't to suggest that you need to isolate yourself, and by no means is suggesting that it is unnecessary to have friends! What is being said is that we need to learn to depend on ourselves before others. As we grow up and move through the different stages in our lives people will come and go. The only guarantee is that you will never leave yourself behind. Those around us will continually influence us in our everyday lives. Sometimes positively and sometimes negatively, this is why you must be confident with yourself. Know your self-worth, and be aware of what is right for you. A friend may give advice in an honest attempt to help, but no one will know what is better for you than you. You need to have your back before anyone else does, friends should be an added helping hand, not your first line of defense.
The problem can be that life can get so crazy. Sometimes its easier to believe what someone else is saying than to judge it for yourself. Or in certain situations its easier to put all the blame on yourself rather than know that you were not in the wrong. Let's not get cocky here, but no one can be wrong 100% of the time. A little faith in yourself and you may be surprised to see that the weight of the world is not on your shoulders, and that surprise! It was not your fault this time. In a society where we are taught to question ourselves, it's important to remember that there are some things that we simply should not question. Like your self-worth, or your right to emotions. Never let anyone tell you that you are not entitled to feel a certain way. Emotions are a funny thing, but they are there for a reason. Maybe not always positive emotions but they still must be worked through. Suppressing them, or calling them "unjustified" is only hurting yourself. No one will know how you feel better than you do, which is why you should never let anyone tell you how to feel. No matter how good of a friend they are, they are your emotions not theirs.
While there are plenty of times in life where we even confuse ourselves, we have a better chance than anyone at figuring ourselves out. No friend, no matter how close will truly be able to experience your emotions and thoughts as you do. This is why we all need to have a little more faith in ourselves. Not be so quick to depend on others to "fix us" or help us through a situation. There will not always be someone there every time you need advice. So let us learn to trust our guts, to allow ourselves to experience our feelings. Let us be our own best friend first.