Hello. Often when we have a low self esteem, we tend to see everything and everyone around us as being negative towards us. It is like a person looking at someone through a dirty window. If your self esteem improves, you will realize that there is love and happiness around you as well. See a psychiatrist who will diagnose and treat underlying mood disorder and may start therapy.

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.

Is it maybe, or you are insecure. It could be only in certain situations or with certain people. If you can still think and dream,  your future is still available for you. If you know what you wanted to become,  and in pursue of those endeavors,  you do not get anxieted about it. It is absence of clarity.