Phone not working.

[Windows Central Question]

I have used the WP(Lumia 520) for about a year or so but since a couple of days it really hasn't worked at all. For example, often it doesn't show me the option to turn on/off the wi-fi, I can't use the internet when the wi-fi is connected because it closes the tab automatically, one App called Age of Empires doesn't show in my data storage but I still receive updates and messages though the game doesn't show anywhere except in notifications, sometimes the phone won't get out of airplane mode, for some reason many songs that I have get errors( I can't remember the errors) saying that the phone can't play it though I could do it just a couple minutes before, and also recently the phone can only turn on when I do a soft reset and if I press the power button once it won't turn on again unless the process is repeated.