Am I sinful for being unable to forgive those who hurt me after the successive problems and traumas I have experienced?

Not forgiving the one who wrongs you is not forbidden. It is permissible to shun the one who wrongs you for three nights, according to the Prophet's (peace be upon him) saying: "It is not lawful for a Muslim to abandon his brother for more than three nights." Forgiving the one who wrongs you is a path to attaining Allah's forgiveness and pardon, and it earns the servant honor and dignity. Allah Almighty said: "And let them pardon and overlook. Would you not like that Allah should forgive you?"