Welcome to the forum! I would try this: Use the voice recorder on your phone. When you wake immediately start talking about what you were just doing. Your only goal at first is to remember three very basic words relating to your recent experience. Maybe the dream was a long adventure with kim while riding horses in France on the beach, while pirates were in the bay, and fresh coconuts are falling about, and some guy is yelling. Problem is you have no recall ability and this memory will fade immediately so yo think you had no dream. You quickly record three words, say "Kim, horses, pirates." Make it a habit even if you only get one word. It could be simply "at school." You will go in steps. Try for three brief thoughts next. "with Kim, riding horses, saw pirates off shore."
You are teaching your brain that remembering this stuff matters to you. Hey brain, there will be a quiz later! Next go back to these three short concepts about an hour after waking. Try to day dream about the memory that must be there. repeat the phrases and add another two thoughts if you can, "coconuts in trees, someone yelling." No, it is not a full memory of the dream, but you are developing the part of your brain that handles this stuff. Work on each phase no less than 2 weeks each.
In the mean time take brief quiet naps or relaxing/day dreaming moments. Even though you do not fall completely asleep. relax enough for your mind to wander. Afterwards act as if those wandering thoughts were dreams. Use the above process to learn to recall your waking mental wanderings in a close to sleep state.
Good luck!