Looking for a manga about a woman who wore red underwear because they were lucky to her job interview and was late because she was helping someone and she fell in love with her boss who was quite a bit older than her but he was sick or something and passed away, leaving her with his son who is close to her age and is in love with her

It's probably not it, but this manga has the older female lead that marries a guy, but he died and she's left with his much younger brother (a high schooler). just realised it's not his son but, XD.

It's called Kekkon x Renai.

I'm in idol hell T.T

It's probably this, or maybe not https://www.mangaupdates.com/series.html?page=4&method=time_added&id=4418

is it Wagaya wa Kiseki de Afureteru?