"Way back when", my DD had a tentative grasp on a not-great robhs when she FINALLY crashed on one and landed on her head. Seriously, it had been coming.
After letting it sit and not working on it at all for a couple of weeks, after discussion with coaches, we all decided to try a series of privates to start at the beginning (especially as they were in "meet season is starting soon let's do routines mode" and not really working ANY drills with her). After some 4-6 weeks of privates (1xweek), DD got it back with like 3-4 weeks to spare before meet season.
It was better than it had been but not great. But her confidence was back. With a move to a new gym brought lots of tramp work and working drills for doubles, and DD decided tumbling was way fun and that she loves to fly.
Her technique is STILL not amazing - maybe level 7 will be the season that she gets those legs plastered together?! Pretty please? That said, she's a fairly powerful tumbler, and is usually one of the first to get floor skills.
So... There's hope? She needs time to heal and time for a slow recovery in order to rebuild her confidence.
Also wanted to add: My DD also recently lost her flight on beam after a series of crashes. She was pushing to meet the level 7 deadline for skills, and kept trying to rush it all back despite her immense fear. Coaches decided no level 7 (bars iffy anyway) and DD completely started over, BHS on a line on the floor. Two months later, she's still working up to doing her BHS on high beam on her own, and her two series are "FINALLY" on low beam without mats. I'm hopeful now that her level 4 season is over, and level 5 mobility is obtained (tomorrow!), and they work those BHS more often, that confidence will build more quickly. At this point, I'm just hoping its all on high beam by June, so there's no pressure or big rush to have it ready for level 7. Anyway, rushing and threats (no level 7!) and begging was not helpful. Time and understanding was.