Was it caused by medication?

In the last month ive had anaphylactic shock twice. My face and neck swelled up. The second reaction was really bad and i went to hospital. On the second occation i had eaten foods maybe containing nuts and fish. On first occation i only remember eating friendly bacteria food although did eat other food also. I belived after the first time it was the friendly bacteria but second time i was sure i didn't eat that. I have never been allergic to anything in the past. Other than these foods i went on a medication called haloperidol. I was told it was 1in a million to be that so i took it again. Within days of taking haloperidol reactions happened. Im of that medication now but sometimes feel like im going to react again. Ive avoided fish and nuts also. I suffer mental health problems which could be making me over worried. Any help would be great. Cheers from tony age 24.