Every single app crashes

[Sean Waite]

Long story short I was trying to flash PACman ROM onto my galaxy s4 however this didn't work so I decided to go back to the normal ROM. Since then I've had every single application crash including x.gapps and system. I really don't know what to do anymore as my device is pretty much unusable. Can anyone help?

 

[Sean Waite]

Sorry yeah I meant stock.
No I didn't factory reset my phone with a custom ROM every guide said to never do that