Please don't dismember your EB based on one doctor's observation.
Screw tails and tail pockets are common in EBs and are manageable most of the time.
Yes this time, it has gotten bad; possibly due to earlier runny stools and secondary infection.
As "1Chumly" suggests, see another vet if possible.
After this round of infections heal; take extra care of the tail.
On a daily basis, EBs need their faces wiped dry 2-3 times and butt/tail pocket wiped at least once.