Is it obligatory to focus on spending on the family, or on accumulating money to redress injustices? And is repentance accepted if one is unable to return the money?

We ask Allah to accept your repentance. As for your concern regarding your offspring and the restitution of injustices, attend to both matters simultaneously. If both are impossible, then the essential expenses of your family take precedence over repaying debt. As for the acceptance of your repentance despite your inability to return the money, your repentance is valid if you are sincere in it, regretful, and resolved to fulfill the rights when you are able. You will not be held accountable for an inability. Al-Qurtubi and Ibn Muflih transmitted this, and some contemporary jurists from the Hanafi, Maliki, and Shafi’i schools have issued fatwas to this effect.