Can the sins of aiding in evil be forgiven if it was in a moment of foolishness and temptation, and what is the solution to get rid of sins that may continue even after death?

As long as you have sincerely repented of this act, there is nothing upon you, Allah willing. For a sincere repentance erases the effect of a sin, as the Prophet, peace and blessings be upon him, said: "The one who repents from sin is like one who has no sin." Repentance consists of abandoning the sin, regretting having committed it, and resolving not to return to it.