It's always best that when you are not using it, close every application that is opened and turn OFF Bluetooth, Wifi and turn On do not disturb. Additionally, You should close every application opened because if its opened then it is messing with your Phone in the background and can give you a virus. Furthermore, check the reviews before you download an app. Just to be Cautious, Safe and Secure.
when you are installing something then it is best to leave it alone. If it is reacting that way without anything being installed, then it is best to leave it alone for at least 5 days. That happened to me too with my IPod Touch. Its because you are over using it.
You can create a new user account and re-download the software. Retry to restore it with a new/different firmware, may be downgrade a version or two. You can also try to use a different computer and attempt a restore. The firmware is available at http://www.felixbruns.de/iPod/firmware/ and do a left shift-restore which then will give you the option to restore with your downloaded version of the firmware. It will work Trust me.
DO NOT TURN IT ON AT ANY CIRCUMSTANCES!!! Place in a bowel or plastic bag of uncooked rice and leave it there for TWO Months ( I know its a long time but its worth it.) Never listen to what the people say when they say that you can leave it in there for only 5 days. ITS A LIE!!! LEAVE IT IN FOR TWO MONTHS FOR IT TO WORK!!!! AND PRAY!!!!! IT WILL work for ALL devices. It helped me when my IPhone went in the washer with my outfit for my Evolution Tour. It should look like this: http://previews.123rf.com/images/volff/v...-Uncooked-rice-in-a-bowl-on-a-white-background--Stock-Photo.jpg https://img.ifcdn.com/images/49c4d58a73d... http://images.huffingtonpost.com/2011-09-23-riceinbag.jpg