Stopping Methylphenidate ER 20 mg

I have been taking Methylphenidate ER 20 mg. daily for about 2 years. Each month I need a new Rx called in because it is a controlled substance. My doctor is great with that. I was prescribed this because so many of my maintenance drug make me tired and this would help me stay awake. I started with 10 mg and felt that did nothing, so he upped it to 20 mg. I learned when he originally prescribed that it was also used for ADHD, (which I had previously self diagnosed; see previous posts) I did recently find out that it is the generic for Ritalin.

Anyway, this month my Rx was called in on time and I heard nothing from the pharmacy. When I called they stated that it was backordered and none of the nearby Publix pharmacies had it in stock. I went five days without taking it. Yesterday it was ready and I picked it up. The problem I’m having is that by not taking it, I don’t feel any different. If anything, I’m staying awake a little better. I had it for yesterday and today’s dose, but I haven’t taken it. I’m a bit confused on why I don’t feel different not being on it, or better yet, why don’t I feel better when I am on it.