Reboot into recovery by turning phone off and holding down the power button and volume down for about 5 sec. Choose recovery and install backup. If you didn't make a backup (shame on you). You will have to fxz the firmware and you will have a fresh new phone but will lose ALL data including pics and music etc.
Follow the links suggested above. Return to stock. The same version you are on now. Don't flash a different version.
Then I suggest respectfully that you read the stickies at the top of general section and learn a bit more before attempting more flashing.
The more you learn and understand.... The easier things will be and the less trouble you will have. Also might save you from bricking your phone doing something you shouldn't.
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Also you can use fastboot to return to stock. Read this guide, and there's a return to stock section for you.