Hi Dear Sometimes amongst all our friends and family we don't feel a part of them, it could be because you are not getting space to share your feelings or there is a difficulty area for people to understand you. Lack of concentration could be because of inattention, recurrent negative thoughts, constant failures or demotivating feelings. Try and go for some exercise in the day, also practice yoga or deep breathing to release stress and increase concentration. Talk to someone about what you are feeling, try and vent out in paper, write your thoughts may be.

Is there any event that has happened in recent past that must have triggered these thoughts. Thoughts are the culprit mostly when we have a negative view about future, others or self we tend to feel depressed.