How do I get rid of mucus in my chest?

[Emk200528]

Okay so I'm 11 years old but I had a really bad flem/ mucus cough and it wasn't building up quickly and I couldn't breather through my mouth I hated it then I researched can you die from it and it came up with some scary answers then I started to feel anxious nervous and i didn't want to do anything vagus either was so scared but then I took 2 steepsills for the chest pain and just as I was boiling the kettle for my boots mucasy cough rememdy I went upstairs to my mums room and I said I can't breathe she said just cough I said but what I I can't breathe whilst I'm coughing she said you just have to keep coughing and if you can't breathe whilst coughing keep on coughing it will be the flem moving up so I did what she said and it worked but to stop I happening again you must blow your nose or unblock it because all it is is snot stuck not being able to exit once your nose is clear u need to spit also I forgot to mention that when you've just coughed up the flem and it's in your mouth DO NOT SWALLOW IT SPIT IT OUT !! I'm only 11 but this was the scariest thing ever that happened to me I was terrified and I did all of this and it worked hope this will help some of you ;)