To Benadryl or not to Benadryl

We're in another one of the many superstorms in the past month that have been killing people with tornadoes, covering hundreds of square miles of farmland with water, drowning cattle, producing high winds that have been blowing houses off their frames and doing nothing to convince the only group of organized climate deniers left in the world—the American right wing—that global weather keeps edging towards new extremes because an Australian billionaire with a TV station and some coal companies say so. Of course there's tremendous, constant thunder all night, and it's going to continue for many more hours.

The roads are too messed up to consider escape. The Weather Service has been beginning all their forecasts for this area with, "This is a dangerous and life threatening situation." Where we are won't flood, but we're surrounded by places that will, so we're staying put.

Roo has stopped trembling, but she's been panting for hours and is wound up as tight as a drum. She's so scared that her muscles seem barely to work, except in spasmodic fits when she tries to find a more effective hiding place, like jammed in next to me. 

So: I'm on the brink of giving her a couple of Benadryls. She's sensitive to them, so I know they'd slow her down, but would they just make her feel awful while still experiencing the same panic? Also, having to get them down her throat in this condition will take something of a struggle, and she won't consider eating anything voluntarily. I'm good at getting the pills down as smoothly as possible, but still. She weighs 70 pounds, so technically she could take three, but I think that would be too much. Two would probably knock her out.

Any experience with this? Please make any comments here, not on facebook, so I don't have to pop back and forth.