How do I deal with constant failure in my life?

Failure is a good thing. Unlike success, which doesn’t carry any information, failure is a great source of knowledge. Learn from it, go ahead. If the next result also is one, learn from that, and move ahead. Even if one does not meet success, ones wealth of knowledge will be a good enough compensation, for, opportunity shall arise, sooner or later.

Failures help you to figure out what went wrong in the previous attempts with that you can do better in the subsequent attempts. One more thing whatever you do, do it with passion by this you love the work you do and it won't give you the feeling of failure.

On one hand, failure is relevant.  Christopher Columbus was a total failure in meeting his goal of finding a shortcut to India, and Native Americans are still stuck with the misnomer of being called Indians. However, his role in world history remains significant. 
 
For things that are genuine failures, you can consider them as being excellent learning tools.  I like this quote to illustrate this point:  "Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better." - Samuel Beckett

Failure is a launch pad for starting life, not ending it.  You have unique talents and insights.  Don't undervalue them.  Good luck.