iPhone 8 won't connect to my Mac even though I have the latest OS installed on both devices

I recently updated my iPhone 8 to iOS 12.0.1 . When I tried to sync my iPhone with iTunes, a prompt popped up saying "A software update is required to connect to iTunes". I found out that I needed the latest version of iTunes to work with iOS 12.0.1 (i was running macOS High Sierra at that time).

After I updated my Mac to macOS Mojave 10.14 and had the latest iTunes installed, I assumed my iPhone would now connect to iTuned. However, the "A software update is required to connect to iTunes" still appeared even though I had the latest stable version of macOS, iOS and iTunes. I clicked on the download button but after 1 minute, the prompt box said that the installation failed because the software is not currently available from the Software Update Server.

My iPhone wont connect at all except for a very few number of times it randomly decided to show up on iTunes after remaining connected to my Mac for 10 minutes.

I'm looking for a solution to this problem as it is extremely annoying.