In clinging onto our ego, have it manage to destroy our happiness?

Ignorant people are always attaching to something; they don't know how to live without clinging to "I" and "mine."

As a result, even beneficial things are converted into causes of suffering.

Happiness is turned into pain; goodness is turned into pain; praise, fame, honour and the like are all turned into forms of suffering.

As soon as we try to seize and hang on to them, they all become unsatisfactory, painful, and ugly.

Yes. But how does one truly destroy the ego? Because not holding beliefs in an effort to be ego-less may very well be the ego in action once again.

Ego thrives on misery. In joy we merge with larger reality and ego is dissolved at least for that moment. Hence, ego will see to it that we wallow in misery after misery for ego's own perpetuation!

When we stand away from true sense and intelligence there starts the problem. The more you are egoistic, the more you will lose peace.