soo i used a console command to unlock a locked cabinet ( it was taunting me i swear!) so does this mean i wont get the hardmode achievement? or can i start a new game and still get it?

The game doesn't have anything in it that makes it so you can't get achievements if you use a console/mod/otherwise cheat.

phew - thanks , thats alot of work to have to start over ...

Cannot be called an "achievment" if any kind of cheat is used, not that I care, I cheat like hell on those irritating mini games.