Travis Kelce used to “lose [his] cool a lot of the time” when he under-performed on the football field. The 34-year-old sports star – who won the Super Bowl with the Kansas City Chiefs earlier this year – has revealed how his on-field mentality has evolved over the years. Travis – who is dating pop star Taylor Swift – said on the ‘New Heights’ podcast: “I stopped caring about stats about four or five years ago. “I just went out there and started to play free and play for my guys. Sure enough, I think that’s the better mentality. You think about it more play by play and what your job is on that…