Vaginal discharge smell

TMI but I have had such bad luck with my down there part. It’s been very uncomfortable for me and hard for me to deal with. But my discharge stains my underwear and makes me smell. I have to wear a tampon all the time or a pad. I’ve gone to the dr many times and they say I don’t have any infection or anything. And that they don’t know why it is doing that or smells like that. Please help me fix it ideas tips anything.