Start your PC, just as Windows attempts to load (spinning dots), press and hold Power Button for 5 - 10 seconds to perform a Hard Shut Down
Do this twice
On the third start Windows will boot into the Recovery Environment and from there you can access System Repair, Safe Mode, Command Prompt... etc.
Go to Troubleshoot - Advanced Option - System Restore
Check to see if you have a restore point you can go back to
Thanks again, it's just scanning for start up errors now as I've found my bitlocker recovery key and it's scanning the startup errors. Once that's done if it's still not working I'll try your suggestion 👍🏻