Large baby!! Help!!

I’m 37 + 2 and was told at my last appointment that I’m carrying a very large baby.. my husbands family all makes large babies all 10+ lbs, including himself. His sister just had a C section for a 12 lb baby.. at my 28 week scan she was already 4lbs 6oz, now they want to check her weight again (I know it’s not completely accurate) this Friday the 22nd. I’m freaking out as I’m a FTM & is this even going to be possible to have a vaginal birth w a baby that large?? I’m just feeling like I’ll definitely end up having a C Section at this point because there’s no point in even trying 😞 Any advice or stories if you’ve given birth vaginally to a big baby especially FTM’s would greatly be appreciated. Also I’m a very small person 5 feet even & extremely small framed 😞