Nick,
Congrats on getting the bites. Thats the best part anyway. Try this to keep them on. After you cast, put the rod but and reel under your arm pit. Then retrieve the fly with two hands alternating right and left. You do not necessarily have to retrieve super fast this way, you can vary your retrieve, add pauses etc just like when doing a one handed strip. When you feel a bite, keep stripping. Keep stripping even when the fish starts thrashing on the surface as coho often do shortly after feeling the hook. Only raise the rod tip when the fish starts to run. I don't know what strength tippet you are using but you may want to use something moderately strong with this method such as 15 lb or higher. If you try it let me know if it helps you as it has for me. One other thing to try is a bigger hook. Hope this helps.
Mike