How can one get rid of the state of anger that leads to cursing and insulting when recalling situations of injustice, and what is the ruling on the words uttered by the tongue in this state when alone?

What you mention is a psychological disorder that requires consulting doctors and seeking advice. If you are overwhelmed and cannot control yourself, there is no sin upon you. However, if you are able to prevent it, and it causes harm to a Muslim and accuses them of something they are not, then this is a sin from which you must repent. But if the insult is proportionate to the injustice and does not transgress the bounds of Allah, then there is no sin in it.