Please Help asap!!!!

[Laxman Nadig]

I'm pretty much a newbie at rooting and stuff. However, I managed to install TWRP and root my new Oneplus 3t using Magisk. I installed the Substratum theme Galaxy Evolution, after enabling and rebooting, most of my apps don't open, they black out and freeze, including settings app, Substratum. Only the main screen of both these apps seems to appear after which tapping anything leads to a black screen. So, I can't reset the phone in settings or apply a different theme on Substratum. Also, when I tried to boot into recovery, TWRP freezes at the Teamwin logo. I tried to uninstall Substratum and Galaxy theme using Titanium Backup and even denying root access to Substratum on Magisk . But, the theme still comes up even without root and both apps being uninstalled after reboot. Also, The device goes into reboot when I long press the power button without the power menu showing up. Please, please help my set my phone back to normal state as I'm freaking the **** out (I wouldn't mind losing my data).

 

[SactoKingsFan]

Are you still on stock Oxygen OS? If so, you can't just apply all the overlays in most substratum themes. Only some like swift black, swift dark and ozone are fully compatible with OOS. Those that aren't fully compatible can't be used to theme syteme UI. It will just result in a boot loop or other issues. You need to flash the substratum legacy rescue zip which will uninstall all overlays.
After all overlays are uninstalled you can use combination of swift black or dark, ozone and JOnePlus Tools (changes quick setting tiles to any color). Use OP3 Blackmod for 4.1.7 on xda if you want black notifications.