yeah i have the same problem i just went into settings and turned off unnecessary option that were draining battery and i also turn down my brightness and turn my phone on battery save mode but my suggestion to u is just go back to the ios 13 u can always just do ur contacts again if there not saved to ur icloud and ur photos will automatically upload to ur account and u can always download the apps again or just do what i do and wait for the actual ios 14 to release and update to that and problem should be fixed