Not all utility operators require longline skills. Many operators do contract work during the summer. Your experience is marketable. Find the right spot and the external load (short line) can be easily taught. It's just a matter of finding the right outfit for you and staying with them long enough to expand your experience.
The vast majority of former military pilots come into the occupation with little experience in single pilot operations. I know my main experience coming into commerical operations was tactical troop movement and working as a military instructor pilot. The main prerequisit for commericial operations is to have basic skill moving the sticks, the ability to fit into an organization, and most importantly, the ability to make appropriate decisions.