straight from dosdude1.com:
'''Important Note:''' 10.14.4 and later CANNOT be patched properly using Mojave Patcher version 1.2.3 and older. If you update to 10.14.4 or later, and HAVE NOT updated your installer volume with version 1.3.0 or later of Mojave Patcher, you WILL NOT be able to get your system to boot after updating! Please read the updates section for more info.
i agree with Dan try an external bootable drive.