Most Helpful Guy
most likely you want scare him off and if he does that's on him not on you and how do you and in order for him to know what to do he should probably experience it at some point so that if it happens a second time he will know what to do0THIS IS NOT RELEVANT ANYMORE
Most Helpful Girl
Of course you have the right.
Does he know you have them sometimes? Just tell him "hey just so you know, I have anxiety and it occasionally causes me to have anxiety attacks. I wanted you to know so you won't be terrified of it ever happens." And then tell him he could hold your hand to calm you down or whatever works for you0THIS IS NOT RELEVANT ANYMORE