No, you aren't screwed. But it will take a couple of steps to recover. I'm guessing you don't have a recent snapshot that you can restore as that is obviously the quickest fix.
So the first step is to get access to the operating system. The OS is a pretty standard Ubuntu server installation, and the password recovery process is well documented across the Internet. This link looks pretty good, though you will have to go to the second half of step 1 since you don't know the current password. Anyway, have a look at https://tipsonubuntu.com/2016/09/02/reset-forgotten-passwords-ubuntu-16-04/.
Once you have access to the command line, the next step is going to be a little more complicated, as we need to figure out why the upgrade failed. One possibility if this is an older system that has been upgraded a few times is that you many not have enough disk space to run the upgrade. Early builds of FindIT Network Manager had a default hard disk size of 20G, which is a bit small for the current versions. So if that is the case, we would need to increase the disk size first since that is quite likely to be the problem. If not, then we would need to do some more digging.
Assuming you have plenty of free disk space, then the next step is to manually run the FindIT installation package on the server to reinstall the application. This will either solve the problem, or generate an error message giving a reason for the failure. Either way, that gives us a next step to work with. There are some limitations on which versions of FindIT you can upgrade between, so it would help if you remember roughly what version you were running. If you don't remember, you can also find out by running the command 'dpkg -l | grep findit' at the linux command line.
I'm assuming that you have some familiarity with using linux here. If you don't, it might be easier to call the support team and have an engineer walk through the process with you. You can find the local contact number for support at https://cisco.com/go/sbsc.
Cheers,
Dave.
