No, actually, this is a very common side effect of taking antibiotics. People also are very commonly allergic to certain antibiotics. Antibiotics also kill off the beneficial organisms in our intestinal tract that are a very large part of our mental health system. It's probably the antibiotics. You should also know that guidelines do not call for antibiotics to treat ear infections unless they are very severe and persistent -- they go away on their own, as do sinus infections, and because of the tremendous overuse of antibiotics it is not recommended they be used for this disease, again, unless it's quite severe. You might talk to you doc to see if he or she is up on the latest guidelines, which aren't new to holistic medicine but are to allopathic medicine, which hands out antibiotics like candy. (They also hand out anxiety meds like candy, too, without considering there might be some other cause, in your case apparently antibiotics. If you look back at the archives of this forum you will see a lot of people who got anxiety problems and sleep problems from taking them).
I agree that it most likely isn't the antibiotic causing the anxiety symptoms directly. But rather your internal propensity to anxiety that the action may trigger. Do you have a psychologist you see? Would be a great time to reconnect. good luck
2 days is likely too fast for that to happen if it would even happen to you. Antibiotics take 2 days to get an effect in your system,
Perhaps it is a kind of ptsd issue that you have when you think of this med. Or maybe you are allergic to it and get anxious afterwards. Possibilities are numerous and answers are likely not going to be available, so in future just request a different med especially if the new one works out for you.