Suggest Treatment For Foul Vaginal Odor

Hello there. I'm 40, 5 feet tall and just under 12 stone (so overweight I know!). Around 8 years ago I had an IUD fitted. I had lots and lots of problems with it and had it removed around 7 years ago. Ever since I had the coil fitted there was a really unpleasant vaginal odour.....I still have this now. I've had swabs which always come back clear but this is affecting my confidence really badly. I feel as though other people can smell me all the time. Please, please can you help? Many thanks, x