Try to get some training, if you can. A lot of basic archery training takes place at short distances, because it allows you to concentrate on your form without getting distracted. I think you need some instruction to get you started in the right direction, or you might just be practicing mistakes until they begin to feel natural. This might be more likely to happen at short distances, because you're not paying much attention to the arrow, which is great if you're aware of good form and can feel the difference; not so great if you're just practicing bad form.
If possible, get some experience hunting small game. It's not as much of an investment of time and money as a big game hunt, but it's fun, you can still eat them (assuming you hit them), and based on your own experience you will know when you're ready to hunt something bigger.