I tried loosening and tightening the nut but it just goes in circles and wont come off or tighten. am i screwed?

 

not possible. either the threads are stripped and the oil pan has nothing to stop a leak, or the bolt is seized. cannot have the situation described above.

 

your threads are stripped out, pretty bad, to get it out, id put some vice grips on the and pull while twisting, you can either helicoil your oil pan (not recomended) or get a new oil pan (recomended cause they cheap)

as far as driving your car... i wouldnt.