I should have read this sooner. . . .
I had a similar problem with mine. first off, I'm assuming you have an automatic transmission. If not, then the solution is easy-- put the car in gear. what I found that worked is I took a piece of angle iron-- the kind that has the holes predrilled in it, and fashioned a brace to stop the flywheel from turning. there are two pretapped holes on the prybar that will accept (I think it was an M8) screw. use these to attach the angle iron to the flywheel. Here are the challenges with this-- the two holes are opposite each other, so you will have to use multiple pieces of angle iron to build the brace-- I bought one piece(4 foot long) and cut two 4 inch pieces off of it and two 3 inch pieces off of it. I then attached the two 4 inch pieces to the end of the longer (remaining) piece and used the two three inch pcs to hold the angle (cross braced.) Please keep in mind that the assembly needs to brace against the sway bar located below the flywheel and should not be held by hand-- doing so creates a nice angle iron pretzel. you should then have access to the main bolt with your wrench (and breaker bar.)
You may want to go ahead and loosen the rockers before you attempt to remove the crankshaft pulley. In the unlikely event that the valves are not bent, this will prevent further damage.
Hope this helps.