Yeah, I know; everyone's favorite type of question. I just need help with making the character out.
I can't read the character before コミ.
What you read as コ is actually a small ュ, so シュミにはしった.
The precise meaning has to be determined from context, but はしった is to be understood in the figurative sense (e.g. someone "fooling around" / having fun instead of acting responsibly).