Welcome! I think everyone has the problem now and again of their minds being too active to fall asleep, and it stands to reason that focusing on something, like remembering dreams, is counterproductive in 'switching your brain off'.

Maybe it's the way in which you're thinking about it? Instead of repeating "I will remember my dreams" in your head, try thinking in a more abstract manner by imagining your dreams and imagining them being too vivid to forget in the morning. That's what I do anyway. It should make your mind trail off into dream-like subject matter, which should send you to sleep.

Hope this helps (and that you can understand what I've written!)