How can I deal with my family members (a father who does not pray and curses Allah, a mother who curses Allah, and a brother who fights Islam) without that leading to my apostasy from Islam?

The greatest tribulation a person faces is the deviance of their relatives. The Muslim finds an example in the prophets. It should be noted that some actions can constitute major disbelief (kufr akbar) about which there is no disagreement. The duty towards such individuals is to denounce their actions, clarify the gravity of their deeds, and explain their legal consequences in this world and the hereafter. One must be patient in inviting them to Allah and advising them with gentleness, avoid gatherings where Allah is disobeyed, hate them for the sake of Allah, and manifest dislike for their actions. If they persist in their error and it serves a benefit, they should be boycotted, while noting that the execution of the apostasy punishment is the prerogative of the Muslim ruler after all conditions are met.