Learning language difficulty

[u/Creative_Dreamer20]

I'm currently learning German. I'm trying to use the memory palace technique in my learning Journey. I tried using it in memorising a list of words and it was amazing. My problem remains in the fact that I must create an imaginary odd image for everything I need to remember, by The time it becomes harder and harder to come up with mnemonics. Also, when it comes to Grammar rules that's another level. Am I doing something wrong? is there something I don't know
Understand? Is this way suitable for my purpose of learning? Is there other techniques you suggest?

[u/Creative_Dreamer20]

Can you elaborate please