Battery issue

Your graph shows a 40% discharge (from 60% to 20%) over a 12 hour period. That is normal, it is not “draining badly”. But why are you only charging for short periods of time? That is not good for the battery.

You are not doing anything to optimize your battery capacity. The absolute best way to get maximum use on a charge, as well as slow the decline of battery capacity long term is to enable Optimized Battery Charging (Settings/Battery/Battery Health) and charge the device overnight, every night. The battery will fast charge to 80%, then pause. During the nighttime pause the phone will use mains power instead of battery power, allowing the battery to “rest”, and thus reducing the need to charge the battery quite as often. The phone will resume charging to reach 100% when you are ready to use your phone; it will “learn” your usage pattern. If you enable iCloud Backup (Settings/[your name]/iCloud - iCloud Backup) the phone will back up overnight also, assuring that you can never lose more than the current day’s updates. Here's more information→About Optimized Battery Charging on your iPhone - Apple Support

iPhone 11 and later models, battery performance --> About the battery and performance of iPhone 11 and later