I can’t say I have encountered this exact situation before.
So if this was my project and I had waited a couple of hours and not seen evidence of any forward progress (I generally monitor the available storage on the system and CPU, Memory, etc. on Task Manager), I would declare the project corrupt.
First backup any files that you do have, just in case you have additional ideas down the road.
Then follow my procedure for corrupt file recovery: Corrupt or Otherwise Broken Audacity Project Recovery