Would it be possible to save some photos I took pointing to the sky? I accidentally left my ISO on 2500 so its just plain white, I tried to bring down the exposure in lightroom but it looks terrible .
Probably not. If all the photosites on your camera's sensor got enough light to exceed full well capacity, then the numbers recorded from all of them are the same.
It's like trying to tell if you got four inches, six inches, or eight inches of rain when all of your rain buckets overflow if more than two inches fell. There's no way to compare how much more one bucket overflowed compared to the other.
Imagine each photosite on your sensor is a bucket that collects photons. The way to get a photo with details is to expose so that some of the "buckets" are mostly empty, others are almost totally full, and most of them are at various levels in between. Details are the difference between how much light hits each photosite. If they're all full, solid white is all you've recorded.