I responded earlier...you became proficient at 20 yds and under through practice...alot of practice, dedication and concentration.
Put that same dedication and concentration to work on shots 25-30 yds and you'll be amazed at what your bow/arrow will do. Get rid of that mental block. Spend a day stumpshooting at longer distances and find out what your setup will do at those distances.
I found out in Wyoming years ago, a 40 yd shot at mule deer in the Prairie is a "gimme". There is nothing between you and the animal but clean air. If I waited for that 15-20 yd encounter, I would have come home empty. By "gimme" I don't mean chip shot, I mean you better take it.
I had a customer who claimed never to shoot past 20 yds, in fact, 15 yds and under were his norm. I cringed when he told me he had a high rack 8pt 25 yds away, totally relaxed, broadside, looking the other way and he passed. If had listened to me and incorporated long distance shooting in his sessions, he might have been dragging that deer out.
We stump shoot together a few times a year and he now has no problem hitting at 30 yds....dedication and concentration. The last 2 bucks I killed were roughly 35 and 38 yds, from the ground. Never knew what hit them.....I can hear the ground shaking now above Fred, Howard, 'Ol Ben and Jack Howard.