Lisa... this never goes away. It changes, like you have only a moment of shame, or glimpses of shame, or rounds of shame, or you feel it like an echo... but it never fully goes away. And there are times you don't have it, when fights go great and you feel awesome, and then it appears again and your thoughts are "what the f***, I thought I was over this." It's okay.
Firstly, the fact that you fought yesterday and are already trying to get over your shame is a really good sign. The thoughts and emotions are still fresh, so it's a bit raw feeling, but lots of folks try to hold on to those shitty feelings for a long, long time because they feel like they SHOULD be ashamed, even when it's time to let those feelings go. It's good to feel them for a short time, I think. They have meaning. But the feelings and the fight are not necessarily a 1+1 equation. Consider this: when you're sparring in your gym, you know everybody. You know the space. You know that you're training, even really hard sparring has a slightly different intention and emotion to it. "Doing well," or whatever you tell yourself in training is under conditions that are not as similar to a fight as we think they are. We think creating the physical conditions, like getting hit a lot, will prepare us. But the emotional unknowns are a big deal. It's incredibly hard to recreate those in familiar spaces. So the fact that you blanked in your fight is not unusual at all.
The way I see it, if you hadn't put in the work and then blanked in the fight, that's shameful. Folks who don't put in the work, that's a shame. But you get to keep all the hard work you put in in the gym beforehand. Losing a fight doesn't change any of that. Kevin and I call it "shitting the bed," when a fight just goes totally the wrong direction from what you know you're capable of. If you wake up and you've shit the bed, you're embarrassed and ashamed, don't want anyone to see it are afraid they will, etc. But it doesn't mean you don't know how to control yourself. It means the conditions for that situation to take place were all in line. There's nothing wrong with you to have performed the way you did. There's nothing wrong with you to feel the way you do. But don't hold either of those as permanent states. Just wash the sheets and move on.