Time Machine problems Reinstalled Ventura 13.7.4

I reinstalled Ventura 13.7.4 and now two years of Time Machine data files are missing and an old deleted partition has reappeared with one small folder of files from the former TM partition plus current TM backups none of which can be restored, copied, opened et and can't be searched. I'd be happy to find the "missing" files, copy them to another drive and reformat the HDD. But I don't want to lose those files I know are in there but aren't showing.