Coffee has a lot of nasty oils that tea doesn’t have.
I notice that if coffee is the first thing that hits my stomach in the morning, my stomach will protest with discomfort, tightening, acidy feeling.
Anxious and agitated ? Well, it’s sort of supposed to do that isn’t it? I mean, it is supposed to rev you up. If you’re not doing anything then all that revving has nowhere to go, but to come squirting out as nervous tics.
Try getting a little active, just a walk or something to get the blood flowing, something for the induced ‘energy’ to do.
Also try not taking coffee on an empty stomach. Whatever’s in your stomach can buffer the coffee to make it less of a shock. I find that even a tall cup of water preceding a morning coffee will make a big difference.
Your mention of quality is astute, too, I think. Starbucks introduced ‘America’ to better coffee than we were used to, but their dark roast style is harsh/bitter/nasty. People unfortunately think that means ‘good’ coffee these days. The harshness is not necessary.
Try to get coffee with a light or medium roast instead of dark. Dark roast exposes the beans to hotter temps for longer and that brings out more caffeine and more of the most bitter oils.
Some people put loads of milk in their coffee to soak up or mask these bitter elements. But I think that’s a bandaid on badly treated beans.