First of all you need to wait not less than 3 minutes on every step.
Secondly if the script really stops working, it means, that your hosting has a limitation on time of running of PHP scripts, and the DB is not unpacked within this time.
You should find out if your hoster have some methods of unpacking huge databases (more than 150 MB) from gz (SQL). Maybe you got some instruments in you CP. If the hosting does not have such methods, you need to ask him to unpack our dumps in your DB. You need to unpack all the files with .sql.gz from !install/backup/.
