What does "comedown" mean?

Native speaker’s answer
Rebecca
A "comedown" refers to a low or depressing feeling you get after feeling good. You use the word when the effects of drugs or a "high" has worn off! It's also called a "crash" when your body is trying to adjust to its normal state. The same applies to other things like sugar and coffee that make you feel good. But then, you lose your energy afterwards. Right before this, the lyrics say, "riding all these highs". So, he's speaking about all the things in life that make him feel good, and he's waiting for it to be bad again - he's waiting for the "comedown". Ex: I had so much coffee earlier! Now I'm just waiting for the crash. = I had so much coffee earlier! Now I'm just waiting for the comedown. Ex: I feel so good and happy right now! I wonder when the comedown will hit me. Ex: Too much sugar will lead to you crashing.