i don't feel well , i am so weak , lonely i feel i...

The lack of self-confidence or personal weakness depends mainly on how far you are bold and active within the society, and your reactions at the appropriate time, but it is important to know that those who do not develop their ability to deal with themselves and enhance their confidence, it will be reflected on them negatively in forms of Fear and  incorrect decisions in life.
In order to strengthen your personality, you have to start by boosting your confidence in and be positive with yourself. You do not have to be frustrated with yourself but rather develop your personality and not allow yourself to be controlled by negative feelings and hesitation. 

Accept yourself, focus on the positive aspects of your personality and set to yourself goals to be busy with. Try to accomplish your goals in life, as it will lead the person to new achievements and thus you will find yourself confidence and gradually the hesitation will disappear. Try again and again to achieve your goals, as you have to know and bear in mind that mistakes do not mean that you are a failure, but mistakes help us learning, so do not be disappoint with yourself when you make mistakes, but re-arrange yourself and your obligations, learn from your former mistakes in order to be more bold in life. Keep practicing and do exercises i.e. relaxing in relaxing, so that you discharge the negative energy inside yourself.