Chosen Solution

When trying to log in the process freezes about 3/4 of the way and now I can’t get past this stage.

Could be several things. We need to know you exact model. You may have gotten an incomplete update or corrupted your system, picked up a virus, etc. Try starting in Safe Mode by holding down the Shift key on start up. Next try starting up for your recovery partition by holding down the Option key on start and run Disk Utilities. Let us know your results for further solutions.