Atomchick - Welcome to SR!
Like you, I was a long time user of opiates with my last 5 years of using codeine I ordered online from the UK. Cost me lots of $. Mine were stronger, 30mg, but I took up to 12 a day, close to your dose, though not as much Tylenol.
I tapered in Dec. 2010 and have been in recovery since. Longest time since I started this roller coast ride with other similar opiates 20 yrs ago.
May people think codeine is not as bad as other opiates, but I found it to be, but maybe that is b/c when I quit hydrocodone 9 yrs ago, I was a lot younger.
Anyway, it can be done and SR is the primary reason I succeeded this time. I am at over 16 months now. The first 3 months are tough with all the w/d symptoms you have read about and then still issues that come and go for months. Even today, once or twice a month, that devil pops inside my head again. I expect to always have to be diligent in my recovery.
Keep posting. We are all here for you. You can do this. You must stop all that Tylenol use. I had surgery last Nov. and prayer my liver had not been compromised by all of my use and was blessed that all was well. I did keep up a good nutritous diet while I used which is probably why, but carried about 60 extra pounds most of those years as well. I am glad I don't live in the UK or Canada. I am not strong enough to keep away from my DOC that is that easy to get.