Yeah , Fresh install will be good. If you try to solve the problem by other means then other problems might come latter. Just backup your database and fresh install your wordpress.
There is a lock file that gets created during the upgrade process. You might have good luck if you remove that lock file and try the upgrade again. This happened with a couple of sites I work on and after I removed the lock file then it all worked. The manual install might be overkill if you can fix this by removing the lock file. You shouldn't need to do a fresh install. Maybe a manual update via FTP if the lock file thing doesn't do it but a fresh install is a bit overkill IMO. let us know if you need more direction or help.
If your are encountering stalling ONLY when you are upgrading, it could also be something hardware related. Be sure to backup your database as others have mentioned. Check logs, check the servers load when doing the upgrade.