have you tried getting into recovery mode and wiping cache partitions?
Hold the power and the volume down button for a couple of seconds. When the screen goes dark hold the power button and the volume up button. It should take you to recovery mode. Once you are in recovery mode, use the volume up and down buttons to navigate and to get to the wipe cache partition option. That should be a great fix for the issue.
You could also try getting into safe mode by holding the power button down until you get three options. Hold the power down prompt on the touch screen and it should go green. Click the safe mode icon and try using that and see how it goes. Safe mode disables third party apps, as it could be a third party app that is causing those issues. Thanks!
Let me know if that helps! Thanks!