Sorry to hear about your bike. Bike thieves suck. Had my bike stolen from my apartment building in my senior year of college - someone just went into the de facto bike room and broke the object my bike was attached to - took the bike including the locks.
I guess your place of work doesn't let you bring the bike inside? Maybe you could ask them about putting a rack just inside the entrance door or maybe putting some cameras up. If you need a new lock, you get a Skunklock to at least fight back against thieves:
http://skunklock.com/
I use a yellow Kryptonite u-lock, which are supposedly more robust than the orange ones. And if I know I have to be somewhere where my bike will be outside, unattended, I will often also carry a heavy Kryptonite chain lock. But these days, I rarely use my bike for transit, since I'm just afraid of it getting stolen, even with the locks.
Also remember with the U-locks, it's also important to leave as little space as possible in them to keep people from stuffing a jack inside it or using the bike as a lever to help break it.