iOS 8.3 messaging is slow and buggy after update from 8.2

iPhone 4S (64GB) Ever since upgrading to 8.3, my messaging app has become really buggy. It takes a long time for the messages list to load for each person in my phone. Also the keyboard is sometimes horizontally displayed even when I am holding the phone vertically. Sometimes the messages in my history won't be displayed. I am in a WiFi area with strong signal and my data is "on". Are others having this issue?