How can I fix my LG G3 from the new Marshmallow 6.0 update?

A

AC Question

I have searched everywhere about a problem I am having on my phone but there isn't much about it. About a week ago, my phone decided to update itself to the new 6.0 software and now it is completely messed up! I do NOT know anything about cellphones and I need help. Here are problems that have happened after the update:

1. Home button and notification toolbar has stopped working. The home button does nothing when it is pressed and the notification doesn't show me anything. When I scroll it down shortcuts are missing and when messages come in there isn't notification icon. (only the 'back' button works)

2. Occasionally it restarts itself. When I am on facebook or looking at messages it freezes and then shuts off and on about 2 times until it doesn't anymore. Sometimes when this happens the screen spazzes out and turns blue than shuts off. When I try to turn it on it doesn't and I have to remove the battery for about 2 minutes for it to turn back on.

3. Developer options will not open!! no matter how hard I try!

If anyone can help me I would gladly appreciate it!!