We've all had it in our house over Xmas.
My mum had hers earlier with mine but it has come back again worse like yours, Mary. She gets it like sometimes and it lingers. She's mid seventies now but has had colds like that since her sixties.
She's even had coughs lasting months before but she also has asthma. If you get a persistent cough there are many things they can be, my mum won't even bother with a doctor for ages because she's so used to them.
Just keep getting lots of vitamin C. It will help. Rest up, plenty of fluids and let your body sort itself out.
With having asthma our GP's have always told us to look for signs of chest infection like yellow/green mucus. If it's clear, they always said it's not a sign. They told us that many years ago because our asthma needed antibiotics when there was an infection. I'm luckily beating such things these days with just extra vitamin C.