I wanted to add this here, for those who might run into this issue of Windows losing connection to Linux.

I was able to connect through the smbclient to a share on my computer. So, at least Linux can access Windows, but Windows cannot access Linux.

I can copy files to Windows from Linux. It seems that something must be corrupt on the Linux system for it not to allow Windows to access it. But, at least I can access Windows from Linux, and am successfully copying the important files over. Very happy right now.
However, I still would like to dive into why Linux does not allow Windows to access it.
Still open to suggestions, but wanted to add this as an Answer, as it did allow me to save my files.