Updating the iphone 11 pro from the restore screen could not be completed due to an unknown error. Before the whole update could be finished,the connection is lost between the PC and the phone.Any help?

My iphone 11 pro went into the restore mode.I dont want to lose any data so i dont want to restore the phone.So i am trying to update the phone as suggested by the Apple support.I succeeded once and my phone was back to normal operation but it didnt last more than 2 days and again my phone is in the same state.So now when i am trying to update the phone,the whole process goes normally but at the end,the connection between the PC and the phone is cut and the update cant be completed.

I dont have the backup of my phone so i am really worried about my memories worth 200 gb in the phone.

Can anyone pl help???