All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If the situation is as you mentioned in the question, then you have become irrevocably divorced from your husband and you will not become lawful to him unless you marry another man a true marriage and he consummates the marriage with you and then he dies or divorces you.
According to the preponderant opinion of the scholars divorce during menses takes place as we clarified in Fatwa 82330.
We also clarified that three times divorce in one session takes place as three divorces and this is the view of the majority of the scholars and that anger does not prevent divorce from taking place if the person is conscious of what he says, as we clarified in Fatwa 84170.
Therefore, it becomes clear that the reconciliation which you resorted to after the three divorces is of no effect Islamicly, because you are irrevocably divorced from him and you are not lawful to him unless you marry another man.
As regards writing the word divorce, it is among the metaphors of divorce and if the husband intends to initiate divorce by writing the word divorce, then divorce takes place.
However, it is better to consult one of the Islamic courts in your country as it is more appropriate for the court to look into such matters.
Finally, it should be mentioned that marriage is an important Islamic ritual so it is not permissible for this ritual to be subjected to misuse and the breaking up of marriage for trivial reasons. In Islamic Law, divorce is the last solution, so how could it be that the husband considers it as the first solution.
It should also be mentioned that the wife has the right to have a separate accommodation as we clarified in Fatwa 84608.
Allaah Knows best.