fccs this thread will continue to go in circles unless you do as instructed.
In one breath you said you didn't download anything now you say you downloaded all kinds of games and apps.
Listen, If you don't want to factory reset (which is not a big deal at all) then start deleting the apps that people suggested JUST FOR TESTING purposes. Uninstall one at a time and test for 12 hours. If on uninstall you see no difference reinstall it and delete the next one so on and so forth.
If you want normal battery life you have to learn to let go of apps that are destroying it.
If after testing all the apps and none of them is negatively effecting battery life do a FACTORY RESET. It will wipe your device clean like you just took it out of the box. It's not a huge deal if you really want to get your device working properly.
With all this said you've gotten great advice. We can't help you anymore unless you do as instructed. If you don't want to listen I suggest you just learn to live with the poor battery life and leave your device plugged in when possible.
This thread is filled with every possible solution so get to work. If you don't want to take anyone's advice stay plugged in and your problems are solved : )