I'm not as old as you, but I've picked up some valuable lessons in my 40+ years:

• the only way to lose weight is to not eat. Preferably as fast as possible by NOT eating at all. Diets don't work, water fasts do. Might cure your cancer and diabetes also.
• sleep on your side and breathe through your nose.
• Running is what you do when you're skinny, not what you do to lose weight. That's walking.
• Full body barbell-weighted linear progression programs FTW.
• Playing sports once a week, like flag football. HIIT if you have nothing else.
• Try to eat clean paleo/keto, its the best long-term health diet.