Does a marriage become unlawful if a girl marries while doubting whether she is still married to another man, due to thoughts and intrusive whispers that come to her about a previous marriage or a forbidden act she cannot recall?

Marriage is not established by exchanging glances or mere assumptions; rather, it has conditions such as the offer and acceptance between the guardian and the husband, and a specific formula witnessed by two witnesses. Therefore, you are not married simply by that, and there is no harm in marrying another person.