White smoke and overheating – tell me I don’t need a new engine

Just got back from a weekend trip to Jebel Hafeet and my 2011 328i started blowing white smoke like crazy after I parked. Coolant level dropped fast and there's this sweet smell coming from the exhaust. I'm honestly terrified it's the head gasket. A colleague at work said I should just sell the car as is, but I've had it for seven years and I really want to fix it properly if it's not too late. Been calling around Sharjah and Abu Dhabi and some places quoted me for a full engine swap while others mentioned using a High-Quality Gasket Abu Dhabi service that focuses on just replacing the gasket without pulling the whole motor out if the block isn't warped. Has anyone actually done that successfully on an N52? I know it's still expensive but way less than a used engine. Just trying to figure out if I'm wasting money trying to save it or if there's a real chance it'll run fine afterwards. Also any tips on what to ask the shop to check before they start tearing things apart would be amazing.