Is There Anyoter Better Way To Stretch My Leg While Suffering From Pain In Heel?

I am a 38 male that is in pretty good shape other than some foot pain. I play basketball about 3x a week and the pain has come on slowly. The pain is on the sides of each heel bone right near the back of my foot. The pain is on both sides of the heel and on both feet. I can hit the spots by pinching about a 1/2 inch up from where the heel contacts the floor and about 1/4 inch each side of the midline on the back of the foot. It does not seem to be the tendon as the pain is over the bone not soft tissue. It get more painful after an hour or so of playing but I notice it more when I get up in the mornings. It is painful and stiff making it difficult to walk when I first wake up. I am having a hard time getting it stretched or loosened up (been trying the bent knee calf stretch as well as sitting and stretching the ankle/foot in different directions). I am wondering if there is a better way to stretch and if I need to stop playing (basketball is really my main form of exercise). Also, obviously what could be the issue and how worried should I be. Thanks - Dan