I’ve learned that my mouth has a ‘bitter meter’; it gives an obvious signal if I’ve had too much coffee, without yet having enough sugar or water, and it’s time to balance that out.
The way to relieve that (turn off the signal) is to stop drinking coffee, and have some water, and/or a piece of fruit.
Typically I don’t need any more coffee for the rest of the day after that point, as it usually happens during my 2nd cup (which is usually my last).
I find this ‘bitter meter’ and the antidote to be fascinating.
I’ve tested it repeatedly; I’m not imagining or mistakenly interpreting it.
If I continue to drink coffee past this point, it just gets worse and worse.
Your body always wants to get back to balance, and it will take steps (including giving signals) to make that happen.
The question is, are you paying attention to it?