Why has a scar after 3 years became infected HELP

hi everyone hoping someone can help. 3 years ago i had an ovarian cyst removed through key hole. the past 4 days i have had extremely bad pain around the scarring on my belly button, not inside my belly button but around it along with swellin and bright red so clearly an infection. saw my GP who referred me to the surgical ward as she was concerned about this but when the surgeon looked at it he was confussd why the scar after so long has became some what infected and why its causing an issue now he said it is impossible so gave me some antibiocs and let me home. two lads later the pain seems to be getting worse and i feel more restricted i cant even bed down im walking hunched over. unsure if this is normal and if antibiotics is even going to work as the GP origiannly said it wouldnt as it looks deep internal where the infection is. any help be appreciated