Allergic reaction question?

About an hour ago I ate something with oyster sauce (I obviously didn't realize) and I have a shellfish allergy. I feel tingling in the back of my throat and like there is a lump. I immediately began to panic and thought my throat was closing but I could still breathe and nothing like that has ever happened to me before. I took benadryl about 20-30 mins ago. If my throat hasn't closed by now (I ate it over an hour ago) is it same to ume I'm in the clear?