PLEASE HELP! I am stuck on the OSX Utilities Menu.

PLEASE HELP! I am stuck on the OSX Utilities Menu after trying to reset factory settings by going to Disc utilities>Macintosh HD>Erase. Then was prompted to go back to OS X Utilities menu and select reinstall OS X Lion but it says it needs 2gbs data after trying to reinstall. Now I'm stuck on OSX utilities menu and can only use internet through Get Help Online option. I do not have any installation discs so im stuck. PLEASE HELP!!