iPhone multiple update failure?

Hi guys .

I have a little bit complicated problem with my dev.

After latest ios update my device started to restart randomly .. After a week i tried factory reset, but nothing changed. After i tried to update it with itunes , still no change . At last I downloaded the latest ios ipsw to my device and in DFU MODE tried to update it with itunes but failed . And after that i can’t do any restore,update, DFU cause i have ERROR 9 in itunes all the time. I tried 3 different cable tryed to download ios 12.x manually again or download it with itunes nothing changed . I am switched off the antivirus,firewall etc .. Nothing . When i turns on the device only the white screen comes with apple logo Aroun around .

Any idea guys what to try ?