Today’s Carson Daly admitted he hit rock bottom last year in his decades-long battle with anxiety – but now the TV host says he’s doing swimmingly because he dunks himself in a tub of frigid water every single day. RadarOnline.com can reveal the former Total Request Live emcee recalled about his torment: “Physically and mentally, I was a wreck, and I thought, ‘Next year I want to get better.” However, the 51-year-old father of four warmed up to self-improvement in a very cool way. “I have a home cold plunge – 40 degrees. Literally two minutes every day!” Carson explained. “It’s really hard to …