When I was a kid my dad let me watch a movie; I had nightmares for a month. I want to watch it again and can't find it.
It was around 1995, definitely before 2000. At the beginning there was a meteor shower, and a lot of polished black stones fell to earth. When people picked them up a tiny "tongue" bit them and they started turning into aliens. I seem to remember something about their skin going all bubbly and melt-y.
People turned into kind of zombies, they lost their will, the virus or whatever made them want to transform. They could recognize uninfected and tried to infect them (I think with tricking them into touching the stones).
Then some folks developed cure and made it into aerosol and wanted to release it at the gathering where the infected were sort of waiting for the main character to completely turn alien. Anyways, this main guy started to peel his face of (final stage of transformation I think) and his girlfriend released the gas and he died. She survived I think, though she was also infected (that's how she got close in the first place), but still had her own will, though it was shown how she struggled with alien's survival and preservation instinct (because she was infected and that part of her didn't want to release the cure and die).
Also, it was dark movie, I think most scenes were happening at night, pretty much alien/zombie/apocalypse type of feel to it.