What does it do exactly when you try to boot normally?
Always seemed to be video issues when I had that happen. I would try uninstalling video drivers and downloading/reinstalling the latest ones for your card. While in safe mode.
Also, uninstall any software you installed recently.
I just went through this with one of my HP's. I took it to my new tech guy and he said the hard drive was rubbish. I assume he is correct and not trying to just sell me a new computer since he doesn't sell computers. I hate not knowing for sure though but I don't have what it takes to learn this crap for myself.
Short of major medical procedures it totally sucks having to be dependent on others.