Is this grammatically correct? What does it mean and can it be rephrased? “ this last phase is so stressful. I can’t even deny it”

Yes, the sentence is grammatically correct. It means that the speaker finds the last phase of a situation very stressful and acknowledges that they cannot deny or pretend that it isn’t stressful. It can be rephrased in several ways, such as: 1. "This final stage is extremely stressful, and I can't pretend otherwise." 2. "I’m finding this last phase to be very stressful, and I won’t deny it." 3. "I can’t deny that this last phase is really stressful." Each of these alternatives conveys the same meaning while varying the wording.