Pred is great like that, makes you feel better in no time. I would have thought a drop from 15-10mg would have been better but 15-5mg isnt a problem when you have only been on it a week.
Good luck starting the Plaquenil. a lot of people on here have had success with this med and I hope they can come along and give you feedback.
I also feel the need to work, as it makes me feel productive too.
Hopefully the Plaquenil will help you and you can keep working.
Let us know how you go on it.