I think Tylenol 3 is Canada's Vicodin. I am pescribed it too for pain which of course I am not refilling. Minn has given you good advice. Talk to your doctor about tapering. You need to be concerned about your kidneys and liver because of all the acetaminophen in them. Just ask your doctor to check you out.
Hi rusky and welcome. You've come to the right place for support. There are two options, tapering and cold turkey. It is just my opinion, but I think cold turkey would probably be the best way for you, especially since your wife has begun taking them. From what I have read here, tapering works best with a doctor's supervision and if the person has someone who can dole out the pills so you won't take too many.
Have you talked with your doctor? There are medications he or she can prescribe that will help ease the withdrawal symptoms a bit. You can also find supplements and vitamins listed in the Thomas recipe here in the Health Pages of this site.
My experience was with hydrocodone, so I think the same advice would apply to your situation. Others who have come off of codeine will probably chime in soon with more information that will help you. Hang in there and you should have some other responses soon.
Best of luck,
Minn