The sensor was cracked at one of the bolts and was floppy, probably why it was able to contact. I'm a bit confused because behind the sensor there were some spacer nuts, and after watching a video of someone replacing the sensor, those nuts weren't there. So I put the new sensor on without the nuts and that's when it ran fine for a while until it started stalling again. Sorry for the confusion.
The replacement balancer is made by Dorman, lifetime warranty. It seems to be the correct balancer, and when I crank the engine, it shows RPM, so I don't think it's the sensor or balancer. If trying to crank it or drive it while the balancer was ****ed up could **** something else up good enough to stop the car from starting, that could be an issue, but I'm stumped.
