Update 12/03/20: The USA is now refusing entry to anyone coming from Europe, for 30 days. So you won't even make it to Atlanta.
According to the link to the embassy you provided you will be denied entry to Jamaica. This will most likely already be executed by KLM staff in Frankfurt. This means you will be denied boarding in the first place.
The only exception would be if you are (also) a Jamaican citizen.
You did not mention when you are flying, so if your flight is only going to be in a few weeks or even days, the situation might have changed completely. Then you just have to wait and go an a day-by-day basis and see what the embassy has to say.
As per your suggestion that you could still only travel to Atlanta, I suggest you search for "skipping one leg of a journey" here on this site. This usually always turns out bad (especially for a possible return flight which will be cancelled by the airline). Since in the US you always have to check your bags again on an international transfer, you could get your bags at least and given the right Esta/Visa for the US you could leave the airport and wait two weeks there. Two weeks would be the minimum period you'd have to wait before being allowed entry into Jamaica. You would then have to buy a new ticket to Jamaica, of course and your return flight would have been cancelled and you would have to buy that one again, too.
With all this said, it might be best to call the airline (Delta in this case, since you booked with them) and see if they can give you a (full) refund.