there's nothing like saddle time to make you better....

some suggestions:

find a technical but short trail, with a number of things at or above your limit. ride sections of the trail until you clear them or decide that it's not the day for clearing them.

ride in the front of the group and find your own line. when learning how to mtbike, i got into more trouble following other folks lines than by doing anything else. sometimes you'll pick a harder way, but you've really got to go with your own flow.

slap the ground with your hands - planting them into the ground breaks bones (as you're well aware, and maybe couldn't avoid anyhow). i don't know how to teach this besides falling more or working on some martial art where you learn to fall and are repeatedly thrown to the ground for practice.

ymmv