Hi. As per me some more details are required to make a complete diagnosis. But on the basis of information provided ,like not able to enjoy anything , these thing persistent for long time, a chronic sadness and getting distressed by small matter ,point to diagnosis of either disthymia or depression
depending on your socio- functional decline.
This is a condition which need a intervention by psychiatrist
who will evaluate the need for medication and prescribe you one if required ,else may only advice on therapy, specially Cognitive Behaviour Therapy
. It will help you deal with your situation and help you come out of it