45yr old female SIDELINED by best FRIEND for LOSER GUY?

I'm a 44yr old female. I'm really angry at the moment. Myself and my friend Kats have lived together this past 18yrs. We are really good friends and her and I are like sisters. We both never bothered much about work. Our days were spent shopping, drinking and hitting the strip around tea time with our face on. We are known in all the bars around here and the clubs. We have bodies of 18yr olds and dress accordingly. We even shared some men and her brother and I were regular friends with benefits. However, here I am, its 6pm and I@m hammered drunk and Kats is gone on a date for THE WHOLE EVENING with some loser shes been sleeping with. I feel so left out. We always sleep with men but they never feature much in our life past the bedroom or the quick releas against the porch door. The back of one heralds the face of another has been mine and Kats Motto. How do i get her to see that shes wasting time on this loser adn that our friendship is suffering?