Hi Suavojr!
I would just read her some quotes from old WT that sound urgent, or that discourage college because the end was so close etc just like todays text, with dates like the 30s-80s. Ask her to guess when these urgent warnings were written. She will likely think they were written within the last few years. When she sees they were from the 60s she will get the point, at least subconciously that these are tired old warnings and there is no need to freak out over them! The reaction todays text had on your wife was the intended one. Create Fear Obligation and Guilt, spurring on further activity, contributions, obedient thoughts etc.
Please remember that IN GENERAL women FEEL and use emotion in a way we generally do not. While you are using your power of reason and logic, she will not, or may not be capable of doing so. Try to tailor your response with this in mind. Facts will not get through, so use things that will make her feel. Thats what the WT and jw.org is all about right now. Just think of all the sappy music in the jwbroadacst videos! Its all designed to bypass concious thought and go right to the emotions.
Also why is she so freaked out by the end coming? Is she afraid for your "spirituality"? Do you think she has a clue about how you feel?