You could try making (or buying) a pistol sling that goes across your back and helps stabilize your pistol when you press it out to the firing position. You could also fire your pistol from a supported position (elbows on table or leaning against a wall with your firing shoulder or arm in contact with the wall.) Alternatively, just recognize aging eventually degrades eveyones' shooting ability . . . I do most of my shooting at 7 yards or less at a silhouette target with a flash sight picture. For me, at close range, front sight alignment to target is more important than slght picture.