Sorry for your loss, and hope you get some recoveries, but in my experience if they're badly frosted they never really recover. Might be worth planting out new seeds directly in the ground for anything that can manage it.

Around my neck of the woods the common wisdom is don't plant anything out until Victoria Day weekend (May 24), and every year I ignore it, and lose a ton of seedlings as a result. Trying to be a little less hasty this year and started hardening things off today, but we've had frost warnings all week so who fuckin' knows eh