I have a slightly different take than everyone else but first - WOW! We have the same kid. Your entire post is very familiar. My daughter also has anxiety (and has since she was little). Although my DD deals with anxiety to some extent on a daily basis, twice in her career the anxiety was so bad that I questioned whether she was done with the sport. The first time was actually before she was invited to Xcel when she was in 4th grade. She was in a once a week rec class. The trigger was her 4th grade teacher but the anxiety bled into every other facet of her life. In gymnastics this meant that she became hyper-fixated on how her leo looked and she changed her entire posture to try to hide herself. She looked absolutely miserable. As this was a once a week rec class, she had ample opportunity to quit but she didn't want to. Meanwhile, she started therapy and learned some coping strategies. The classroom situation also improved and so did everything else, including gymnastics. Towards the end of 4th grade she was invited to join the Xcel team.
The second time was during her senior year. The trigger this time was her gym starting when her coach abruptly left (and is now USAG permanently banned so lots of drama). The new HC was a coach that she had always struggled with. The entire gym was in flux and adapting to the new HC. The way the anxiety manifested with my DD was same as you describe - loss of skills, poor self-esteem, 'lazy', borderline insubordinate, would repeat the same drills over and over and over and not make progress, etc. It was nuts because while this was happening, she was also actively interviewing with D3 teams. The feedback she received from the college coaches was all very positive and consistent. Then she'd go back to the gym and have the worst weeks of training ever. She talked of quitting just before the season was to begin. At times I wanted to force her to quit. We thought things would improve once the season began but nope. She went from going to Westerns jr year to struggling to qualify for state senior year. Then she got injured, then the pandemic and during this she STILL wanted to keep trying for D3 gymnastics.
So here's where my advice differs slightly. I think you need to make sure it's not the coaching. I say this because the words your DDs coaches use with her were the exact same ones that my DD heard over and over and eventually she just shut down in the gym. Above all else, my DD needs to feel respected and valued. My DD has a hard time with people if she doesn't know where she stands with them. Related to this - if she feels like the authority figures in her life don't like or respect her, she really struggles. This was at play with my DDs 4th grade teacher and also during her senior year in the gym. My daughter is also very sensitive to non-verbal cues - sighs and eye rolls yes, but also raised eye brows, body posture, side glances, slight tightening of facial muscles etc. She knows when she's either not liked or is viewed as being a nuisance or a pain or 'lazy'. I wonder if this is also what's going on with your DD too. Maybe all she needs is a gym change. And therapy. My DD started therapy too and it helped a lot with new strategies for coping and advice on how to communicate with her coaches.
My DD stuck it out at the gym until she left for college this past January. She loves her new team. It took awhile to get used to new coaching and the way college gymansts train (much of it is self-directed) but this is typical for freshman. She heard a lot of 'I don't like the way you learned that, try this instead'. She got stronger. She learned new skills. She made new friends. She fell in love all over again with the sport. And she decided she would not return to her club gym for summer training.