So much discharge

UGGHH why do I have so much.!! I can’t even workout or walk a lot or so basically anything withought having discharge. It’s not something new I’ve had this problem for years.! I’m 18 btw n I had a baby c section but it’s been like that since before i even got pregnant. I have to wear a panty liner bc my underwear mess up with the discharge 😭 n I’ve gotten tested before so I don’t have anything but lately it’s been brownish discharge not my period because it’s already passed so I think I should get checked again and it smells after I shower like a couple of hours after I start to smell down there again. 😭 I am on birthcontrol iud.!