Precession would make the effect of pedaling work opposite of the way you think it would. If you had to turn the drive side clockwise to loosen, it is left hand threaded. It is an ISO bottom bracket, and from the picture , it looks like a Campy AC-H. I would try to chase the threads to see what the real damage looks like. My gut is telling me that it will be fine with a new bb installed. Just make sure you pull it once a year and regrease the threads. The old bb was stuck due to galvanic corrosion, which could have been avoided by renewing the grease (or anti-seize) in those threads once a year or so.