I agree, make a board bow or two. Back them with hardwood veneer or a slice of the board turned around and glued back on. I really think that many failures come when fellows try to make 60-pound bows out of wood that will better serve a 40-pound bow. Wood can do two things when strained: bend or break. The proper thickness and width in any individual piece of wood will determine which of these two things happen when you string it up and pull. Personally, I'd rather have a working bow that pulls 40-pounds than a pile of broken sticks that I WANTED to be 60-pounders.
Frustration? get used to it. Satisfaction? yup, the first time you make a bow that works the satisfaction will bring you to your knees............start with a stick and make a bow, a weapon, a tool that can feed you......it is magic, really. So, stick with it. Be frustrated. Never give up.
piper