How is Antonio's experience of bad luck depicted in The Merchant of Venice?

Antonio's bad luck is vested in the fact that his merchant ships were destroyed at sea due to some or other unforeseen event. A variety of reports are given about the matter, as illustrated in the following excerpts:

Why, yet it lives there uncheck'd that Antonio hath
a ship of rich lading wrecked on the narrow seas;
the Goodwins, I think they call the place...

Salarino was responding to a query from Salario about news from the Rialto in Act III, Scene 1.

TUBAL
Yes, other men have ill luck too: Antonio, as I
heard in Genoa,—
Hath an argosy cast away, coming from Tripolis.

Tubal informs Shylock of Antonio's ill-luck in the same scene.

Sweet Bassanio, my ships have all
miscarried,...

The above is Antonio's letter to Bassanio about his misfortune in Act III, Scene 2.

What complicates Antonio's situation even further is that he signed a bond with the Jewish moneylender, Shylock, for the repayment of a loan to the value of three thousand ducats within three months. If Antonio should forfeit, Shylock can claim a pound of his flesh in restitution. Antonio loses his fortune, so Shylock seeks restitution, as Antonio explains in his letter to Bassanio:

My creditors grow cruel, my estate is
very low, my bond to the Jew is forfeit; and since
in paying it, it is impossible I should live.

In this instance, Antonio comes across as distraught since he realizes Shylock will be unrepentant and recalcitrant. He knows Shylock hates him and the forfeit has given the moneylender an ideal opportunity to avenge the wrongs Antonio has done him. It is, for this reason, that Antonio feels that he will not live since Shylock will insist on having his pound of flesh and kill him in the process.

It is ironic that Antonio should find himself in such a desperate situation since his only desire was to help his best friend, Bassanio, in an attempt to win the hand of the beautiful and wealthy heiress Portia. More irony lies in the fact that Bassanio urged Antonio not to agree to the bond, but he insisted, as seen in the following portion of Act 1, Scene 3:

BASSANIO
I like not fair terms and a villain's mind.

ANTONIO
Come on: in this there can be no dismay;
My ships come home a month before the day.

One could perhaps surmise that Antonio's overconfidence was challenging destiny and he overplays his hand.