Can God remove His protection from me because I said about a man that he harassed a woman, without verifying it, and out of fear of problems?

This matter you mentioned is considered slander, but since you have repented from it, we ask Allah to accept your repentance. Scholars have differed regarding the expiation for backbiting. Some stipulate seeking forgiveness from the wronged person, while others hold that praying for them, seeking forgiveness for them, and speaking well of the slandered person is sufficient, which is what a group of verified scholars have stated. Therefore, strive to seek forgiveness for this person and speak well of them, and that will be sufficient for you to expiate your sin. Be confident that Allah will not expose you with this sin after your repentance.