Apps not working

[aaa15]

Hello!

For a week now apps stop constantly working (Messenger, Facebook, Google Chrome, Camera and others). I get the message that App has stopped working, then I get black screen and phone hangs up. Sometimes phone restarts itself automatically. 

Yesterday I made a reset and liberated some space on the internal memory. Today the problem reocurred. 

Can someone please suggest what to do? 

[MarlonUk1]

try to perform software repair using Xperia Companion

also to make sure you reformat your sd card

[aaa15]

Thank you for suggestions! How do I reformat SD card?

[MarlonUk1]

2 ways

1st: settings>storage>sdcard>reformat

 or

just place it in a memory card reader and reformat using a desktop PC

[aaa15]

I did as said but the problem persists. I guess there is nothing else to do than return the phone...