I've stocked up on Potassium Iodide tablets for the child to avoid cancer after the nukes fly. I don't think we'll be hit soon in the US, but it's getting a lot more likely.
It's only really useful for nuclear accidents where the primary radioisotope release is I-131. It's not a magical radiation protection shield (for example against Cs-137 or Sr-90 released as a result of nuclear weapons).
As someone who also thinks about the world a lot, I know it is easier said than done. But it helps to mentally separate the things that you can control and the things you cannot control. Then try to accept the things that you can't control.
You cannot directly control Trump or the US army. You can protest, go on strike, boycott, call your congressman/senator, love your neighbor, be there for your kids.