I suffer from the same issues. I haven't figured out how to make the dreams longer, but I find when I fail at making love with girls, it's a result of
I discovered that every time I opened my bedroom door, it became a portal to a new dimension.
so i got this funny issue..
Whenever i LD i loose lucidity and im about to wake up then i join again and get lucid
Be careful as well due to the concept of "false memories". Humans can actual gain memories so to speak of events that never actually occurred.