Alas, at the present moment, we are not aware of any cough drops or throat lozenges that are free of added sweeteners. The least offensive are Olbas Lozenges, but they have Isomalt as their third ingredient and are mildly sweet.
You can drink Throat Coat tea, Rooibos tea, or hot water with lemon. You can also gargle with salt water or apple cider vinegar. Essential oils and herbal remedies can also be helpful. And never underestimate the value of sleep and rest.