What's the difference between "knock down" and "knock out?"
Answer from a Native speaker
Both of these are boxing expressions. Losing balance without losing consciousness is referred to as being "knocked down." When the fighter becomes unconscious from a powerful strike, he's referred to as having been "knocked out" or "KO-ed." The singer here says she is knocked down, but she is back on her feet so she isn't knocked out. Essentially, she was given a strong blow but is still here, fighting. Ex: My opponent's blow knocked me out. Ex: Failing in love always knocks me down.