Word for being disgusted by but unable to stop looking at something
Solution 1:
One might exhibit morbidity, or possess a morbid curiosity, morbid fixation, or morbid fascination with such things:
morbid, adj.: 1. having or expressing a strong interest in sad or unpleasant things, especially disease or death
Note that morbidity means something quite different in medical jargon.
Solution 2:
Consider train wreck
a chaotic or disastrous situation that holds a peculiar fascination for observers
Solution 3:
compelled: driven or urged forcefully or irresistibly, often against one's will.
For me, once you're a painter, you're constantly compelled to look at the world as a potential subject for painting.
O accursed hunger of gold, to what dost thou not compel human hearts! - Virgil