What is the ruling on dealing with the Islamic bank in France, and are its transactions halal, and is it permissible to deal with a usurious bank under the mentioned circumstances?

We ask Allah to ease your affairs, and may the afflictions you mentioned be weighed in the balance of your good deeds. As for dealing with an Islamic bank, the ruling is based on the method and conditions of the transaction, and the fundamental principle in Muslim transactions is permissibility and lawfulness. Given your need, there is no harm for you in dealing with an Islamic bank. As for interest-based (usurious) banks, it is not permissible to deal with them except out of necessity, and there is no necessity when there is an alternative Islamic bank. It is forbidden for a Muslim to deal with interest-based banks if it is possible for him to deal with an Islamic financial institution.