Help android update gone wrong!!help

[chriswb2]

ok i tried installing cm7 on my lg optimus one using rom manager.it rebooted and was stuck on flash mode.i found out how to go into emergency mode and the screen went into emergency mode and fixed the phone.what im wondering is did it load the back up rom that rom manager made?because now my phone is stuck on fast mode again because i was curious and went to emergency mode.can i put another rom on my sd card and load it in emergency mode? ps these are ideas im new to android