Does my existence matter ?

Every time I feel low , the question automatically pops out of my mind. And each time I try to find the answer to I find myself to be depressed and sick of the life.

But do I really need to care what does other think of me that is the fear of unknown.  Does my existence really matters . The answer may be a yea or no depending on the psychological state of person . For most of yes it would be a big yea. But somehow under the line I feel that the matter of my my existence doesn't really bother anyone . Its just another day in their life whatever I am alive or dead. For some of may be  big blow but the impact remains to few weeks to months . What after that ???