Washer shutoff valve is calcified and I can’t remove it.

I soaked it over night with CLR and removed all the calcification, but it still won’t budge. I’m guessing it’s calcified inside, too. I also tried to unthread the flathead screws on top to replace the whole thing but they’re frozen, too, and I’m close to stripping them. I hit it all with WD-40, too. I know a torch is an option, but I don’t have one and I’ve read you can warp everything. What can I do here?