My FP1U doesn't work!

Suddenly my Fairphone no longer works. All applications (including Firefox) crash, almost always during the calls the screen goes black and back to work only by pressing the on/off button for several seconds .
If you restart the phone, it spends several minutes before working.
The keyboard does not respond to commands, as well as the screen .
What can I do? Is there a solution or do I throw it up? It has only 1 year and a half , it is a Fairphone 1U, it never fells and was always held up very well .
I have kaspersky as antivirus .
Thanks for your help and sorry for my English.


You could try booting to safe mode to see if the issue also occurs when all 3rd party apps are deactivated. If you have the crashes in Safe Mode too than try a hard reset (erases everything).

But first of all backup all your important data.