Will a person be held accountable for supplicating against someone with evil, and Allah has answered his supplication? Is there a sin upon him for that, and what should he do in this situation?

It is not permissible to transgress in supplication (Du'a), but supplicating against an oppressor is permissible. If your husband wrongs you, there is no sin upon you if you supplicate against him, as long as you do not transgress the prescribed limits of Islamic law. However, refraining from supplication and exercising patience is better, because the supplication of the oppressed is answered. Therefore, it is advisable to be patient and not to supplicate against a Muslim, especially a spouse or a relative. We advise you to supplicate for your husband, asking Allah to grant him sufficiency, good character, and to settle his debts. In the Hadith: "Nothing averts destiny except supplication (Du'a), and nothing increases one's lifespan except righteousness."