I have a moka pot but I guess I am doing it wrong -- maybe I should not fill its coffee compartment to the brim? is there other way of doing it? -- because the coffee that gets out destroys me: heart palpitations, slight arrhythmia, headaches, and energy crash. I can't drink too much caffeine but light doses (i.e. the Americano) actually help me and energize me. It's really weird.
What's good about the aero-press and the French press btw? I am only just trying to understand the landscape.
Look up Moka Pot Voodoo on YouTube. It'll sort you out.
Americano means nothing - its just diluted strong coffee (eg espresso, moka pot). You probably need to learn how much actual coffee your body can handle.
I handle very little, so have a 1 cup moka pot which takes 9-10g of ground coffee. And that's pushing my upper limit. My body can usually handle better a very unsatisfying 6-7g brewed. I need to find some good decaf... (though I have a line on Laurina coffee, which has half as much caffeine. Hopefully I can get some soon).
French press is just a really easy way to get a great cup of coffee. You don't even need one - you could just make cowboy coffee (grounds in hot water) and carefully decant it out at after 5-10 min. Look up James Hoffman french press method. His aeropress series is good too.
You also need to learn that all of this stuff that everyone says is just drug addict self-talk coping. You only actually get a boost at first, and then your body adapts and is in caffeine deficit and is just trying to get back to baseline with more coffee.
The healthiest way to do any of this would be to try as you said (but likely unsuccessfully) to limit your coffee intake to 2-3 days a week, so that you might actually get a kick rather than just sustain your addiction. Once a week as a special occasion might be more successful. It should be treated as a healthy person treats alcohol...
I'm not even joking with all this drug addict talk.