What line do you have on it now? And what kind of distances are you throwing with fly, leader and fly line?
I think overlining will probably help you if you're having some trouble casting with a fast action rod. It will slow the action of the rod down a bit for you and you'll be able to feel the rod load a bit better. And it makes it a bit easier to throw large wind resistant stuff like bass poppers a it easier.
But for the price of a decent new line, you might want to consider getting some help with your casting first. It would be a great investment if you're new to this. You might also look around for a free casting clinic, or if you have a local fly shop that you use, maybe they could take you out back for a freebie or two.
Local fly fishing groups and your state's Dept of Fish and Wildlife webpage would also be good to check out. Most groups have casting clinics, and there are also free intro to fly fishing events listed on F&W webpages that might be going on near you. And often there is an informal casting clinic on the lawn before meetings, where you might be able to try out a different weight/taper line on your rod.
You can do a search for local clubs affiliated with the Federation of Fly Fishers here (they also have a list of certified casting instructors you can search for by clicking the "Instructor Certification" tab in the menu bar):
Locate a Club
Local TU Chapter search:
Council/Chapter Search | Trout Unlimited - Conserving coldwater fisheries
A fast action rod may be a bit more difficult to learn on, but the advantage is that it will grow with you as your casting improves. As you're able to carry more line in the air, slower action "beginner" rods can begin to feel kind of wimpy. You have a nice rod, so if you can tough it out a bit and get a little hands on help with your mechanics and timing, you should be hitting fishing distances (40-60 feet) pretty quickly and have enough reserve power to stretch it out longer as your casting improves.