Prednisone takes over some of the body's production of certain hormones and so this is why dropping pred is normally done at a slow rate to enable to the body to restart producing these hormones again. I only ever drop my pred my 5mg every two weeks then once on 5 mg drop to taking every other day for 2 weeks and then every 3 days for a week and then stop. This seems to work for me and I don't experience any withdrawal effects.
You should start to notice an improvement in the withdrawal symptoms in a week or so as the body will have kick started it's own production of hormones.