can’t restore iPhone through Mac!

I have an old iPhone which has been erased except for the passcode and I cannot remember it! I spent all of last night trying to restore the iPhone in recovery mode through my Mac. When going to restore, it says it needs to update and once it starts updating my iPhone will back turn on and download stops. When the iPhone turns back on it is disabled and when I return it recovery mode the restore no longer continues but just ‘loads’. I’ve done this 10 times and I'm not sure what else to do. I just want to get into my old iPhone! What else can I do??