ok.
this problem didn't happen initially when I started using Cura a week ago.
it only started when I opened the profile menu to try and save a cusom profile.
that's when it took about 10 minutes to unfreeze and since then every time I tried loading Cura, even version 4.8, I had this issue.
Removing Cura and reinstalling it didn't solve the problem.
I then created a new windows user and Cura opened quickly for that windows user, just like it did with my original windows user when I initally started using cura.
The moment I tried to open the profiles menu (i.e., the drop down profile menu from the right pane) the problem appeared again.