Never should you allow your past be an inderance to achieving new heights.
Yes! You were let down by the person you trusted the most, you won't be the first person to be dejected and obviously won't be the last.
The past is just a shadow casted to obstruct the light at the end of the tunnel , you need to really let go of the past to br able to see new exploit.
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Because you failed at your first attempt doesn't mean you are a failure. Perfection comes into view only when you have tried and failed but you refuse to be a failure.
All you need to do is sit down and recall where you had it all wrong and pick it up again and again until you are satisfied with the result.
Rome obviously wasn't built a day