IOS 11 major bugs. What do I do?

I recently updated my iPhone 6s to ios 11. Huge mistake. These are the bugs.
1) Occasionally, the phone will start glitching (turns black) and it keeps doing that until I turn it off.
2.) My phone is frozen. Right now it is. There's one notification at the top of my phone and it won't go away. It won't me sign in at all and I can't shut it down. I tried using my mac to shut it down but I need to allow access from my phone which I can't do.

Vufvutvfuvtu

Try installing the iOS 10.3.3 IPSW by googling it or watching a tutorial on how to downgrade using IPSW. Then use it to go back to previous version until new update for iOS 11 drops.