While my reply is late (I'm new to this forum), I'm answering anyway, in case someone else has the same problem.
There are two things to try, as a first-step diagnostic process:
•Try to start in verbose mode (press command-V while the Mac starts, until you see a black screen with text in it). When the start up process hangs, the last few lines shown on the screen may indicate the problem.
•Try to start in safe boot mode (press the shift key until the Mac begins to start). This should start the computer without loading a lot of stuff (including Paragon software, I think). Then you may uninstall Paragon from there.