Maybe I should answer "How do I not handle failures in life".
We have the tendency to attribute missed goals/targets/opportunities as things that are wrong with ourselves. I 'am' this-or-that. That is not an empowering conclusion. The ironic thing is: it's you drawing that conclusion. Where are the real life facts in there?
There are none, it's just a judgment. That leaves you with the possibility to draw other conclusions.
Note that I am avoiding the term 'failure'. Maybe it's better to use the more neutral 'breakdown'. You set out to accomplish X, you did not accomplish X -> There is a breakdown. Next step is to analyze what was missing: what lead to the breakdown? What changes will lead to success next time?
At the same time you take responsibility for the breakdown: you can declare what was missing, if necessary apologize for not doing things, make new resolutions and do new promises for next time.
Note that you do exactly that in other areas of life. For example, you were playing a game of volleybal and missed the incoming ball because your position in the field could've been better. You notice that (or your coach does), maybe say 'Sorry guys I missed covering that corner,' and correct it for the next ball coming. There you may be perfectly able to leave the "I'm wrong" out of the conversation.
So why not try that in other areas of life?