Ok, so I haven't been practicing WILD recently because I've focused more on MILD. I went to sleep at 2am with the intention of waking up early in the morning to do a WBTB. I woke up at about 6:30am, got off my bed, went downstairs, and drank some water. I then went back into my room and just sat there for a few minutes, telling myself that I will have a lucid dream. I then tried to go back to sleep while saying some mantras like "I will become aware in my dream and I will do a reality check". I lied on my side and suddenly, I hear a sort of high-pitched sound from my right ear (since I was lying on my left side and my left ear was buried on the pillow). Then I started seeing like a white spiral on the back of my eyes. Then my legs started to feel weird and kind of numb. I assumed I was going into sleep paralysis so I just lied there motionless and tried to see what happened. Everything that I just described - the sound and legs-feeling-numb and the spirals - all happened like simultaneously. The first thing to happen was the sound coming from the ear and then the rest happened at the same time. Eventually, everything was normal and the spiral that I saw disappeared, as well as the sound. Anybody explain what just happened to me?

Note: This was not an intentional WILD. I was only trying to do MILD.