You gotta cut down on weed before bed,
happens to me too. Unfortunately it also drastically lowers my chances of becoming lucid.
IME I haven't been able to retain dreams at all while smoking weed, maybe occasionally one or two, Even when taking dreaming supplements that normally drastically alter my dreams, Like kirkii, I still will not remember any dreams at all.
The best option is to take breaks when smoking weed, I find as long as I don't smoke everyday I can remember tons of different dreams every night, and attain lucidity a few times a week.
When I smoke weed occasionally, once every 3 or 4 days, I can usually remember my dreams anyway. As long as I don't smoke everyday.
So I suggest taking a small break, and just see what works for you.
Expect nothing, Receive everything.
"Experiment and extrapolation is the only means the organic chemists (humans) currrently have - in contrast to "God" (and possibly R. B. Woodward). "
He alone sees truly who sees the Absolute the same in every creature...seeing the same Absolute everywhere, he does not harm himself or others. - The Bhagavad Gita
"The most beautiful thing we can experience, is the mysterious. The source of all true art and science."