Is a relationship that involves both parties addressing each other as "my husband" and "my wife," exchanging sexual conversations and images, including images of 'awrah (private parts), considered Islamically permissible and akin to marriage, based on a mutual agreement for future marriage despite current impediments?

A woman is not considered a wife merely by promising to marry or exchanging titles. Marriage has its pillars and conditions, such as offer and acceptance, and the guardian's contract in the presence of two witnesses. This woman is a stranger to you. What occurred between you, including sexual conversations, exchanging pictures, and viewing private parts, is a transgression of God's limits and a type of fornication (zina), based on the Prophet's (peace be upon him) saying: "Indeed, Allah has decreed upon the son of Adam his share of zina, which he will inevitably attain. The zina of the eyes is looking, the zina of the tongue is speaking, and the soul wishes and desires, and the private part either confirms or denies that." It is incumbent upon both of you to repent to Allah and sever this relationship immediately. If marriage is facilitated, then so be it; otherwise, each of you should go your separate ways. It would have been appropriate to ask before embarking on such matters, as Allah Almighty says: "So ask the people of the message if you do not know."