Hi,
It's strange that liveupdate is not present under Programs & Features.
Download liveupdate setup from the following location:
ftp://ftp.symantec.com/public/english_us_canada/liveupdate/3.3.0/
After live update installs please register it as guided above
Do you have original setup files?
After the successful live update install, try to repair SEPM with the help of original setup files.
If the above steps didn't help please pass on RORU logs, it would be present under temp folder.
Logs can help us to find out why SEPM repair is rolling back.