missed oil changes

due to covid and other circumstances, I failed to have my oil changed last year on my newish car. totally my fault and I understand I have caused myself a ton of money here, but just want a second or their opinion. my oil was obviously really bad – took it for a change and the guy said I’m doomed. having white smoke upon startup and then okay rest of day. took it to dealer and said I can try flushing engine but will prob need to have engine replaced. had engine flushed and guy said engine looks fine, really nothing bad came out of the flush. car was a little better for a few days and now back to lots of white smoke. one mechanic said it’s not the engine, it’s anti-freeze dripping on engine or whatever, but two others said that’s not at all the problem. is replacing my engine the only option now??