A tension filled grip, especially from having the shaft too much in your palms, will kill your entire swing. It stops your wrists from hinging naturally and then works its way up your arms and into your shoulders and locks up your entire swing.
Although you might not know it you have the ability to control the distance on each of your clubs, use the numbers game to figure out how long you should make your backswing to hit each club whatever distance you want
Turn your 8-iron into a sand wedge by opening the face and playing the ball like a normal greenside shot