I think you need to get back to your doctor for further help or at least talk to your pharmacist who will know the details of your case. I have no idea what sort of after dinner party sickness would need treating with an antibiotic and an anti histamine. Usually people whose lupus is confined to the skin are perfectly well otherwise and react to medicines just like anybody else can react except that there are certain medicines they would be normally advised to avoid, in case they make the lupus worse.
People with systemic disease would avoid the same sorts of medicines for the same reasons and then would need to be careful about other medicines including OTC meds, in case they interact with what they are already taking for their lupus. Reactions to all medicines vary widely in the total lupus population just as they do in the general population so there's not much that applies to us all and we are each individual despite having the same diagnosis.
For stuffed up noses from ordinary colds I use capsules with oils like menthol and eucalyptus in them that you can break on a pillow, but I don't know if that sort of thing would be suitable for you. You can buy this sort of essential oils for use in inhalers or burners too and there's always Vick.
I hope you'll be feeling better soon