How do you know if it’s bronchitis, pneumonia or something else?

15 days with a cough and green Phlegm and kinda runny nose but when I lay down stuffy nose. I noticed Feb 24 my throat started feeling weird then I got my cough the next day. I have an appetite but after I eat something i feel like I need to throw up so cough sometimes till it comes up. No fever my throat was a bit sore and tingly in the beginning but not anymore. Sometimes when I’m laying down I have a hard time breathing but I don’t know if it’s because my nose is stuffy. I don’t have insurance so I don’t want to spend money I don’t have on a doctor. 😩 Don’t know how true it is but my husband said he saw somewhere that said green mucus usually means sickness or something like that.