I do  not know since when you are experiencing these symptoms, but if they are of recent onset then you are most probably suffering from depression. You may be depressed mood due to some crisis in your life or you may be suffering from clinical depression.

Hello. The description you have given, appears to be presence of some symptoms of depression. If you are suffering from low mood most of the time a day? If you are losing interest in previously pleasurable activities? If you are not able to concentrate? Suicidal ideas? Negative thougjts? Are you facing all these symptoms and many more other of these kind. Then it may be a concern that need to be addressed immediately. A professional help can guide you about how to manage these symptoms and whether medication is necessary. Even diagnosis of the problem is also very important for proper intervention plan, which again a professional can help you. Depressive symptoms can be handle without medications, depending upon the severity of symptoms.