A five weight rod can cast a fairly big fly a #8 I cast on my 3 and 2 weight rods. Catching pan fish is especially fun on 1-2 & 3 weight rods. I mainly used to fish a 5 weight but now go with the ultra lights. Taking nothing away from your 5 weight and your enjoyment of fly fishing. Look at Lefty Kreh fly casting video's will help you or get with a knowledgeable fly caster/instructor.
Good luck and stick with it, I am also a self taught fly caster. Don't give up it is a wonderful method of fishing, I have left conventional fishing long ago.