Welcome ProphecyWatcher! Hope you enjoy your stay here 
First things first, congratulations for having published a book about your dreams! Hope you had success with that one. 
Secondly, about your DR, it’s just about this: like in everything else, often things are just as hard as you think of them. I’m sure no single member on this forum needs any kind of military device to remember his/her dreams at night.
My guess on your recall during the 2004-2007 period was that dreams were strongly connected to the urgency to recall them in the morning somehow, and you indeed did recall them effectively every day (I presume?). But when you’re not aware of the process, it can go just like the way it came, and some event broke this link. But I’m totally confident this link can be repaired, with effort and practice.
Many people came to this forum, or other LD communities, with very bad DR: they only recalled about a dream a month, or worse, they didn’t remember any dreams at all from a long time. I were among those too 
But we all dream several times a night, that’s for sure, and you do too, so remembering those isn’t at all impossible, you just have to get back the hang of it like many others did. 
We have a BIG remembering dreams topic, where tons of info about DR is stored, I reccomend checking it out ;D