Do you exercise or get any physical activity during the day? Do you have a job that is very mentally demanding?

I find that if I don't get any exercise and have been studying all day that my chances of having a lucid dream are very low. I'll still have vivid dreams but my mind cannot make the connection.

However, if my body is physically tired (like after a night of binge drinking), but I was more mentally relaxed, it almost feels like I'm prepped and ready for a lucid dream. All I can say is if the current methods you are taking aren't working, trying something different, just keep mixing things up until you find something that works.