We have previously published on this website a number of fatwas about divorce (talaaq) issued in anger, in which we explained that anger is of three levels:
Mild anger, in which the husband is annoyed and upset by what his wife has done, but that does not prevent him from thinking rationally and deciding what is the best thing to do.
In this case, the divorce counts as such, according to all scholars.
Extreme anger in which the person loses control and does not know what he is saying or doing, and he becomes like one who is insane or crazy. Divorce issued in this case does not count as such according to all scholars, because he is like one who has lost his mind.
Extreme anger in which the person does not lose control and is aware of what he is saying and doing, but he cannot stop himself because the arguments, insults and fighting have gone on for too long.
This is the type of anger concerning which the scholars differed as to whether a divorce issued in this state counts as such. The most correct view is that it does not count as such, as was stated by Shaykh al-Islam Ibn Taymiyah and his student Ibn al-Qayyim (may Allah have mercy on them).
Ibn al-Qayyim said:
Anger is of three types:
That in which the person loses his mind and is not aware of what he is saying. Divorce does not count as such in this case, and there is no scholarly difference of opinion concerning that.
That which is not so intense as to affect a person’s understanding the implications of what he is saying. Inthis case divorce counts as such.
That which is intense and strong, but not to the point of losing his mind completely; however it is so intense that he does not realize the implication of what he is saying, and he regrets what he did once the anger passes. This is a matter that is debatable and the view that suggests that the divorce does not count as such is strong and valid.
End quote from Zaad al-Ma‘aad fi Hadiy Khayr al-‘Ibaad, 5/215.
What appears to be the case from your question is that the divorce you uttered was of this type, in that you could not control yourself or what you were saying, even though you were aware of what you were saying and understood what it meant.
Hence your divorce does not count as such according to the more correct scholarly opinion concerning this matter.
But if your anger was of the first type -- and you know better about your situation than we do -- then it counts as one talaaq.
To sum up: if you issued the divorce in a state of extreme anger, it does not count as such. But if it was a case of ordinary, mild anger, then it counts as one talaaq.
And Allah knows best.