Huge trouble remembering my dreams!

Hi,
So before I knew anything about lucid dreaming I was an avid dreamer. I would go to bed every night and look forward to having another adventure in dreamland. In the morning I would wake up and immediately remember three dreams or more. Then I found out about lucid dreaming, and I got a dream journal and started recording my dreams. The first ten pages or so of the journal are jam packed with detailed dream descriptions. But as the journal entries become more recent, you can see that I have been just briefly describing dreams, from a couple of sentences down to just one, or a few words and now I can hardly remember anything?
What am I doing wrong? (I also happen to be on a dry spell as far as LDs go.)

I also happen to have as of yet untreated ADD (Attention Deficit Disorder). I am on the waiting list for getting diagnosed and medicated but that was hardly an issue for me in the past as far as remembering dreams. The only thing that has changed is that I have started taking some over-the-counter brain/concentration/memory medicine, some lecithin and daily vitamins whereas before I never did take those. I don't suspect these are the cause though, as they would probably serve to improve memory and since for a while I could still remember dreams perfectly even when I took them...

I also started taking Niacin (Ironically to help induce LD's) a few days ago and I also stopped because it promotes non-REM sleep and I can hardly remember anything, not even little bits and fragments of dreams... But my problem goes back further than a few days that's for sure. I'd say I've been stuck like this for the past three weeks.

What is happening to me?!?!?! T_T

It's possible it's just a coincidence. Even if you have a tendency to remember your dreams, your bound to come across a day or two where you don't remember anything. In fact we all have many dreams every night, but won't remember a majority of them... only the ones that are fresh in our minds as we wake up.
Dream recall will vary from person to person, however. Some may remember most of their dreams while some people may not remember any at all. The main point here, I think, is not to worry. Just try to keep still as you wake up as movement will hinder your dream recall.

Try writing them down as you wake up throughout the night. Even if it's just a scribbled note or two, they should be fresh in your mind then and your notes should be enough for you to make a more detailed entry in the morning.