Does divorce take place by saying "no" when asked if one is married, or by saying "I hated and regretted this choice, I will choose another, I will invalidate it" when anxious, or by saying "I retract and they remain with them and I take half the dowry" when angry, knowing that the speaker did not intend divorce in any of these cases?

The divorce you mentioned does not take effect because you did not intend it. Your statements: "I will annul" or "I will choose someone else" are a promise of future divorce, and it does not occur unless you enact it. As for denying your marriage and stating that you are not married, if you meant a complete marriage, then your intention is correct. Otherwise, it would be a prohibited lie, but it does not divorce the wife unless you intended thereby to initiate a divorce, which you did not intend. Therefore, the woman remains under your marital bond. We advise you to abandon these delusions, as they are from whisperings (waswas).