Locked session "error An internal error has occurred" A month's worth of work in limbo

Hello, I was into a month’s long session when I was asked to upload a file . After I uploaded the file it got stuck with a rotating icon and now the error “error An internal error has occurred” I tried all suggestions. I have the .json file of the session, but due to the limitation of Google’s upload, the 10.5MB file just crashes a new session. I even used a Powershell cmd to convert the .json to plain text and the file did not go down in size. I have a paid service here and apparently no support. I have been at this recovery now for 13 hours and have gotten nowhere. If the full .json could be read I feel that this would have been resolved many hours ago.
Any ideas?? I hate to lose all this work. Thanks

Quick follow up… I divided the file that was converted to text via powershell to two 3mb files the first uploaded fine and the second half crashed the session with the same error.