Despite Portia's speech on the quality of mercy, Shylock receives little at the end of the play and leaves a seemingly broken and unredeemable man. In Twelfth Night, a similar failure to bring Malvolio into the fold of happy characters also occurs, but in Shylock's case the punishment seems even harsher.
Despite the antisemitism other characters espouse, the play does not seem to share that prejudice, giving Shylock a dignity and a humanity as great as any others in the play, if not greater. He has been long-suffering but has cautiously guarded his treasures.
At the end of the play, he loses his bond, his other material wealth which he must give to Lorenzo who has eloped with his only child, and he must abandon or alienate himself from his Judaism. He bears the knowledge that Jessica has taken a love token he shared with his dead wife and traded it for a monkey, has married and will have children outside the Jewish tradition, and that all his labors will profit his enemies. As Portia and the Duke hand down his sentence, Shylock claims:
You take my life
When you do take the means whereby I live.
On the surface those means are simply his ability to earn a living, but in Shakespeare life and live are not usually that simplistic. The means by which Shylock has lived includes all the things by which he has nurtured his identity in a hostile city. He has no choice but to consent to the punishment, but he leaves the stage saying he is not well.
If Shylock survives much longer after this moment in the play, it is implied that he will not be living so much as waiting to die, an utter stranger to his home and self, mouthing other nation's prayers, and denying the faith that had sustained his life.