Unable to log in after installing Mojave

I have a MacBook Pro (15 inch, late 2014 model I think) which had never been upgraded from Mavericks. I just installed Mojave via the Mac App Store and now it won't let me log in.

It boots up fine and takes me to the login screen, but when I enter my password it gets stuck on the spinning wheel icon (the normal loading one, not a beach ball) and never gets beyond that point. I've left it for almost an hour with no progress. The mouse pointer moves, and controls like volume and screen brightness still work, but other than that all I can do is force it to power off by holding the power button. If I type in the wrong password it rejects it, and if I type in the right one this happens.

I've tried several times - one time the "What's new in Mojave" pop-up appeared in the corner, and I clicked Show just to see what would happen. It opened Apple's site in Safari, and still had all of my bookmarks etc intact, so it seems that my data is still there. I was still unable to access any other applications, including Finder which seemed to not have launched. It also didn't seem to have loaded my System Preferences as tapping the trackpad to click didn't work, I had to press the button. Closing Safari took me back to the loading screen. Attempting to login in Safe Mode does the same thing.

Is there anything I can do to get it to work? This is the only user account on the machine so if I can't access it I'm basically locked out. I have a Time Machine backup from immediately before I installed Mojave which I'm assuming I could restore to take me back to a working Mavericks machine, but I'd rather get Mojave working than have to do that.

Thanks for any help!

 

I'll be honest - I don't know. I've never updated to a whole new OS version before so I just went to the Mojave page on the Mac App Store and followed the instructions. After downloading it showed the apple logo and progress bar and seemed to reboot a few times. The process probably took about 25-30 minutes.

I'll try doing the other things you suggested, thanks!

 

No luck, sadly. Still doing exactly the same thing. Unless I find a solution soon I'll just try restoring my Mavericks backup .

 

Since I can't log into my Mac and don't have access to any other computer right now, I don't think I can make a bootable installer. I will try reinstalling the OS through Recovery mode though.

 

Reinstalling Mojave didn't help - it still does exactly the same thing. I'll try looking online a bit more but if I don't find anything in the next few hours I'll just try restoring my Mavericks Time Machine backup.