Johnny - Step away from your TV!!!! (I know what you mean about AGT, though - I haven't watched at all this year. I won't watch until they ban kids and singers from competing.)
Get outside and get some sunshine. Go for a walk, run, or bike ride - get your heart pumping. Do a random act of kindness for someone. Make a list of all your grateful for.
When you find yourself thinking negative thoughts, STOP yourself. It's not easy, but you can train yourself to do it. There are lots of strategies - just google it. Try various suggestions to find a strategy that works for you.