I’m a high soprano, and I usually hover around in the high g high a area. I was sick with the flu for three months months for which I was unable to talk. Around a month ago, I regained my speaking voice and the lower half of my voice range. All region is coming up, but I can’t sing part of the song because of this issue. I have waited a LONG time, but my falsetto hasn’t returned. Is there any way I can get it back?
I'd recommend you see an ENT. It is possible you could have vocal damage (although not super likely, so don't panic just yet). It is also possible you just forgot the coordination for falsetto, as you say you didn't sing (well, couldn't) for three months. Does any sound come out at all when trying to bridge your passagio? You can try imitating Minnie Mouse to refind the coordination, or possibly a prepubescent male voice-crack.