There will be a reason behind this feeling or behaviour of yours, which you are not able to identify and rectify it. Perhaps a Psychological Counsellor might help you in that.

Well the symptoms you have provided shows that you suffer from low mood, sleep disturbances, not able to concentrate and fearfulness which looks more towards a clinical depression.

Hi, you seem to be disturbed by something, it could be some recent events or a pile up of many past negative events. A detailed evaluation in person by a Psychiatrist will be necessary to rule out Depression or Dysthymia. You will benefit greatly from counseling or specific therapy to help you rid yourself of these negative feelings . With counseling you will be able to learn to deal with external situations in a better way as well as manage your feelings better. You can explore the reasons why you feel this way and be able to have clarity to deal with it. With that you can start to perceive things differently and learn how to lead a happy , contented life. You may/ may not require medication. I would suggest you visit a Psychiatrist at the earliest to be able to deal with this. Hope this helps, All the Best!