Great advice from your friends; I will try to add a couple things that have helped me.
First, when does your shoulder hurt? It could be from a lack of exercise, but it could be another issue. If it last more than a week, you should get it checked. I recently went through rehab for an impinged rotator cuff. It may sound odd, but it was probably caused by a lack of exercise, followed by shooting, or work. Does it hurt when raising your arm above your shoulder? Does it hurt when pushing out with the back of your hand against a door frame or wall. Try it while standing relaxed, arms hanging down, push against the wall. If either of these results in pain, you should have it checked.
Shooting routine: I limit practice to every other day at most. Same with strength or running exercise; one day on and one day of rest.
If you do not have a public range available, try to find a few Traditional Archers to shoot with, they may have a place or know of one. Next, check to see if there is any State, Federal or public land where you could take a portable target, and get in a little practice.
Practice routine: When getting back into it after a layoff, I will shoot from 10 yds. for 30 min. without a target. Picking a spot, focus, draw, anchor, and release in one smooth action; working on rhythm and timing. I might do this for several weeks or longer, until I am satisfied, everything is being done right. I am a believer in what Howard Hill said, upon release do nothing, with the bow hand or release. The bow should be still on target, and the release hand should be next to the face. Fred Bear shot much the same way.
Establish a few simple goals, write them down. Follow up by reviewing them, and measure your success. Stay committed and positive.