Is is bad to hold in a mucus cough in the chest? Will it ever go away if i hold it in? Also what can i do to help this cough i cant breathe without coughing

(19F) For the last few days ive had a bad cough in my chest. Its a mucus cough. I cant breathe, eat or talk. Im going crazy. I physically cant get myself to cough it up and spit it out i find it so nasty i cant do it. I try to hold in the cough so hard, but every time i breathe i feel like coughing and i have to breathe carefully constantly. Sometimes the mucus comes up into my throat but i just swallow it quickly. Idk if im actually swallowing it or its just going back where it came from. Today it got worse and when breathing my chest rattles and vibrates. I have constant slight pressure in my chest, propably the mucus. Im surface breathing constantly and i feel a bit dizzy sometimes from holding my breath in so i dont cough. Will this ever go away if i dont cough it up...? Also is it bad that my breath is rattling and i have pressure in my chest?