Try and remember that an awful lot of people have taken an awful lot of animals over the years with traditional equipment--everything from 35# on up, and with all kinds of arrows and broadheads too. Even before anybody ever heard of "FOC" or, for that matter, fiberglass, carbon, or FF strings.
Now, having said that, I think the underlying issue is feeling confident enough to shoot at an animal with traditional equipment. I think this is something that most former compound bow or gun hunters feel when they make the switch to stick and string. I'm sure that everyone will agree that the only way to get confident is to shoot, shoot,shoot. If your setup hits where you aim it, and has a reasonable amount of kinetic energy (sounds like you do), you will be FINE. And remember to BREATHE...................