the way these things work usually, is that if there is a class you hate, everyone else hates it too. maybe your professor sucks, but con law is definitely "unique" as far as 1L classes go. i felt the same way about civ pro last year. when you hate a class, you have to make a conscious effort to work that much harder, because it wont come naturally. i wish there was a simple answer, but you just gotta grab yourself by the balls, and force yourself to work.
as far as supplements go, far and away, the best one is by erwin chemerinsky. its expensive, but it'll get you through any 1st amdt class you end up taking, (i doubt u will though), and is pretty useful if you ever get the urge to read about roe v wade or something, (u probably wont, again). anyway - its a good one. and good luck.