Do you snore? I once saw some research suggesting smoking (of any kind) can cause you to snore, which would prohibit you from dreaming. If your journal is staying empty for 2 months, thats a problem, make a habit to at least write down something in there, like- "I can't recall any dreams tonight, but I did have a feeling this morning as if I did have a dream, but didn't remember it". Writing in my journal, no matter what it is, tends to work wonders for me.