That's rough Vanessa, and I can sympathize. I've mostly wrestled myself which can be just as devastating but I've also had impromptu catfights as well, mostly in college. The one that comes to mind most was against an ex-friend and roommate. We'd originally been close when we moved in, but living together had put strains on our relationship, and truthfully we were both atrocious at communicating with each other. Snipping got frequent, we'd each start doing things just to annoy the other till essentially we were loathing each other. But neither of us wanted to be the one to move out as the apartment was nice, location was perfect, and rent was fairly cheap.
Finally, one night, when our third roommate, the peacemaker and sweetest girl ever, was out on a date, we had our big falling out. It started with arguing about the dishes which then turned into everything we had grown to hate about each other. Words got nastier and cattier till finally she slapped me and we broke out into an all out fight. Initially I was fairly confident as I had taken some grappling classes and was taller, but she had some surprising muscle on her, having done dance most of her life, and we didn't hold back. In the end she had managed to strip me naked while she was topless her self and was dragging me by my hair around the apartment, taking me to places where some of our grudges stemmed. It was humiliating. Finally she was bending my arm and said she'd only let go if I promised to move out by the end of the month. I was so devastated by my loss and in so much pain I agreed and she let go, delivering one more kick to my side.
Initially I planned on going back on it but she made it clear that if I didn't, the next time our roommate was out, she'd "educate" me again. So in the end, my pride in tatters, I moved out like I promised. That has been my most devastating loss, not because it was a blow out, I held my own for much of it, but because of the emotional toll for sure and the loss of that perfect apartment.
In terms of getting my ass kicked bad in a competitive situation. I lost a competitive biker event match really bad, which involved me getting stripped and humiliated in front of a crowd.
And might I say that I'd love to hear all about this biker event!