iPhone 8 with 11.2.6 crashing and draining

The battery is nuts since updating to 11.2.5 and even worse with 11.2.6. I have an iPhone 8 that I got 2 months ago and the battery is all over the place. This morning I had it charged to 100% in my car, walked 15 minutes while listening to an audiobook and it crashed when I got to my desk. Battery down to 10%. I had it plugged in charging yesterday after it died and it was only up to 54% after charging for 4 hours. I thought there was supposed to be some great fix for battery life. This is the absolute worst I've ever had with any iPhone and iOS since I started using iPhones.