iOS9 Update freeze, problems with posted solution

I am using an iPhone 4S. I received notification yesterday that the iOS9 update was available. After doing a quick Google to see what was being said about the operating system, I decided to update - I did not see any warnings at this stage about the frozen screen issue. As with many others, once I get past the part of set-up where I'm invited to choose a wifi network, the screen freezes on "slide to update."

I have seen the solution posted online: If the Slide to Upgrade screen won't go away after you update to iOS 9 - Apple Support Unfortunately I am unable to apply it. I do not have a back up on iTunes (hindsight being 20/20), and iTunes will not allow me to make a back up. When I attempted to make a back up, I received an error message stating that the iphone is not set up. I'm not sure what is required, but I won't be able to set up the iPhone using the device, as it is frozen. I am also unable to use "restore iPhone" on iTunes, as apparently "Find my iPhone" is set up. I attempted to disable this on iCloud, but that doesn't seem to have worked (after I used the option to "erase this device").

I would very much appreciate any advice. I'd even settle for being told that there will be a download via iTunes in a period of time that will fix the problem. I'm a bit concerned that I may have a permanently broken phone.