Hello,
With any new version of iOS there are always maintenance and re-indexing tasks to be performed. It should settle down in a few days. These are the standard steps for short battery life:
1) Have you tried a restart? If not, do it now.
2) Go to Settings > Battery > BATTERY USAGE BY APP to see the apps that are consuming your battery.
3) Check “Battery Health” in the link:
iPhone Battery and Performance
4) If all else fails, consider a battery replacement:
iPhone Battery & Power Repair
If the phone is overheating, see this:
Keeping iPhone, iPad, and iPod touch within acceptable operating temperatures
Good luck.