Are you unhappy about something or someone?!!! Do feel left out in your family  or among your friends?!!! There could be something which is bothering you.

Seems like there are some thoughts that are bothering you. There are times when despite trying to think positive our mind reminds us of certain negative things or situations which may make us feel this way.  First of all you need to vent out to a Psychologist or someone you can trust, in your case I would recommend you have sessions with a Psychologist so that things can be sorted out. Moreover a Psychologist will teach you some relaxation techniques, you can also consult online for a detailed first session so that exact decision can be taken. If you have any negative thoughts concerning yourself you must also consult a Psychiatrist. This does not mean that there is something very wrong but treatment will make you feel much better.

Loss of interest, decreased concentration and attention, feeling low and disturbed sleep or appetite are some of the signs of depression. Consult a psychiatrist who will assess you in detail. If you are feeling suicidal or hopeless, seek professional help immediately. Try some relaxation techniques like yoga, meditation and deep breathing. Indulge in hobbies. Spend time with people close to you.