I hear you, first, stop beating on yourself, myself and many others here suffered and continue to fight addiction. You first start by asking for help is a big step.
There are a few folks here that can help you with your taper, your not ingesting that much, I'm not minimizing this but you stated you tapered before, you can taper and jump off over a period of time. I personally would not do the meth route, you shouldn't IMHO. Thing is, as you stated, you were clean about a week when you tapered so you already know whats in store for you.
I too worked clinical and facilities management at 2 different rehabs years ago and thought I could manage. I had to forget what I thought I knew and listen to others who have successfully got clean and continue to help others who want to get clean and sober.
OK, you are not alone, I would also suggest some type of support group, 12 step, faith based,etc. No one is judging you and thinking your judgmental, we have been there. We suffer the same pain.
I have gotten clean and relapsed more times than I care to admit. I was not ready, finally I was done.

I always hated when I was told to get humble, but I did. I was a dope fiend for 20 someodd years and other drugs even longer. It took me 20years to amass 5 years clean and I still was not done. point is after using took me to prison, 5 od's and dieing twice in the ER I finally got clean, lost my fiancee to this disease a year and a half ago and after a brief dance with pain meds today I am sober. That was the pep talk.
What are your plans for your taper?, as I said there are good people here who can help you but you really need to want to because they will invest time to help but will not if your not really ready.
I can tell by your post you are distressed, and have concerns about the longevity of the use. Its not like it was just a couple a months, Last time you tapered what dosage and length of time did you do?
As I previously said, there are some here that could help you better than I. I personally never abused percs and vicodin but sure abused Oxys and Heroin.
Do you have enough to do a slow taper?
oh I did not see your other post........
Rich g