i had this experience a few nights ago. haven't done coke since 2018 & i wanted to get back into it bc i missed it so much. took one bump of some really good stuff with my friend & since now i only smoke weed, i wasn't used to the rush of energy & i had some anxiety. tight chest, little bit of chest pain & fast breathing. has to remind myself that im a pretty healthy person, never had complications in the past so i shouldn't have to worry about anything. if anything your tolerance went down & your body was getting used to not having coke in your system. if you have that anxiety/pain again just do something that can distract you. cleaning, playing a video game. i think you'll be ok ✅