IOS 12 bugs on iPhone 8

I recently updated my iphone 8 to ios 12. It has done nothing but slow my phone down. It causes my phone to crash, my speakers don't work unless headphones are plugged in. My camera doesn't show up. All my apps are slow to close. Also when it crashes a tiny grey bar appears, on the black screen. I've been looking for a definitive answer but can't seem to find anything about the bugs with the ios 12 that came out about 3 ish weeks ago. I tried factory reset with a backup from the ios 12 and that didn't fix the issues at all. Any help would be appreciated.