Mainly in speech, we can invert an expression such as 'I am', 'he is', 'we are', etc, to emphasise the statement and make it stronger. The form of words will resemble a question, but will not be ended with a question mark, but is usually ended by an exclamation mark. Often an exclamation such as 'Oh boy!', 'Jesus!', 'God!', 'My word!', etc will precede it.
Was my father glad to see you? - question.
God! Was my father glad to see you! - emphatic statement, my father was
very glad to see you.
Am I tired? - question, possibly rhetorical (only I know the answer).
Christ! Am I tired! - emphatic statement, I am very tired.
Am I glad we finally found you? - question (am I glad, or am I not
glad?)
Boy, am I glad we finally found you! - emphatic statement, I am very
glad we finally found you.
Does she look nice in that dress? - question.
Does she look nice in that dress! - emphatic statement, she looks very nice in that dress.
Subject - verb inversion in English