Bob,
Seven and a half years ago, at age 67, I had a heart attack. and emergency quintuple bypass surgery followed by ventilator induced pneumonia. When they woke me from my medically induced coma, after a few more days, I began inpatient rehab. My first day in rehab was learning to stand up from a wheelchair. I also had to learn to feed myself again.
Within two weeks, I had improved so much that I was given a free pass permitting me to wander anywhere I wanted in the rehab hospital. I eas released the following week, enrolled in outpatient rehab and was walking two miles a day two weeks after my release. Two months later, I was back at my normal gym lifting weights and doing calisthenics. Two months after that, I was running again.
Give it time.
Ira