Please explain what exactly happens during withdrawal from xanax (alprazolam) and benzo's?

Lots of bad things: Including seizures and delirium (dt's), as well as elevation of blood pressure to where heart damage or stroke may occur. Xanax (alprazolam) is a benzo, and has a more severe withdrawal syndrome because it is so short-acting. Benzos should never be abruptly stopped after chronic use, but should be tapered or replaced with a longer-acting drug that is tapered. Anticonvulsants can also help.