Eleven years is a while to be addicted to anything.
However you're addicted to ephedrine. It's a dangerous stimulant but not half as psychologically addictive as amphetamines (adderall, dexedrine, crystal meth), it doesn't make you half as high as those, and it's not physically addictive.
Just taper your dosage over a period of 2-weeks to a month. There shouldn't be any dangerous withdrawal. Even if you were to suddenly quit, you'll probably just deal with one whole week of sleepiness/lethargy.
Stick to reducing slowly. If you have trouble doing this, try drinking coffee as a substitute.
It should work out. We're not talking painkillers or even alcohol. This is as easy an addiction to quit as any.
And once you're off the ephedrine, you can always try caffeine pills and coffee. Caffeine is another addiction, but it's 1000% safer than ephedrine ever will be.
Hope this helps!