I'm thinking that the abortive attempt at reinstallation has upset the HDD.
You really need to boot it up from a source other than the hard-drive, and I wish you'd said you needed data from it before someone advised you to try the repair (which would never work if you have CPU overtemps as you do).
See my previous advice on methods for alternate boot sources.
Yeah, sorry. A few weeks ago I got a new HDD put in, as the old one had pretty much completely died. Lost all of my data, but almost all of it was reinstallable, or on my USB.