Depending on your current release and how it's setup, there are releases that are designed for shooting with a loop. They can be adjusted to get your hand closer to the string. If for some reason, you can't get the release adjusted to the point of keeping your anchor the same, then you will have to shorten the bow's drawlength.

Also, I've seen people shooting very long loops, that didn't need to. It's usually because the loop stretched a lot or the loop maker wasn't careful to keep it short. This can make a huge difference. I prefer to make my own loops (catfish loop). They won't stretch and have many advantages over a traditional loop put on at an archery shop. When I make them, I can customize the length so it's just long enough to get my release on, without knocking the arrow off the bow. Since it won't stretch, it stays there and is as short as a loop can be. Combine that with the right release and my bow's drawlength can be left right where it would be if I attached to the string.