Speed wd is much easier than opiates to get over.
You need sleep, and food. My best suggestion would be to take a Friday off work and Monday. Give yourself 3 days to do nothing but sleep and you should be feeling much better.
I was on adderall, dexedrine and meth for 15 years. I've detoxed no short of 50 times over those years. Every time its the same thing... Sleep - Food.
Good luck
Have you discussed this with your doctor? I would hope he would help you taper down on this......