Trying to get photos to download from iPhone 8

I have an iPhone 8 that is out of memory and about 1,000 pictures/videos. I'm trying to download to my computer but keep running into issues. When I try to do the automated download, part way through I get an error message that the computer cannot connect to the phone. So I tried to cut and paste the files and at first that seemed to work. Photos from the phone appeared to be deleted as I went through the process but then I would hit the same error message. After reconnecting the phone, the old photos I deleted would reappear, and they would also be on the computer. Is my phone corrupt? Any help would be appreciated.