Will The Nail Grow Back After Detaching From Nail Bed?

my toenail got detached from the nailbed just now.it was due to trauma (i hit a metal door). there was blood coming out of my toenail but not profusely. i've already put pressure on the toe to stop the bledding.half of the nail is still attached.about 15 years ago i had the same condition on the same toenail, it was also due to trauma but the nail grew back on.right now i'm afraid that the nail will not grow back again and what can i do to prevent permanent damage?