Well cinnamon is not the standard desktop of Trisquel. So it is not very
likely that anyone is experiencing your issues.
From my experiences you now have two possible approaches (given you have
another working (!) PC for searching the www):
1) Look through all logs in the shell after boot and try tho find the
possible cause,
or (less time consuming)
2) Create a backup of your personal data and re-install the system. One can
waste an incredible amount of time to fix a screwed up system. Possibly you
get it to work again but often strange side effects stay.
