I had CABG in 2023 at age 71. It's scary, but they know what they're doing. I did not have sternum pain. I had back pain and a muscle relaxer pill helped. A friend loaned me her recliner with electric controls (electric controls are a MUST). I slept in it for at least 6 weeks. Much easier for me than my bed, since you can't push yourself up with your arms. Walk as much as you can, now and afterwards, even short walks. Also, use the incentive spirometer. I loved cardiac rehab. You will feel better than you do now. Best wishes!!