My son had to retire early because of his high pressure job's stress factor. His diabetes was out of control and this lead to the fore mentioned issues leading to the bi-pass surgery. He is not able to care for himself without assistance. His surgery is about three weeks old now.
You can buy a medication dispenser ($200.00+) where you load many days' worth of medicines in separate compartments for each time of day. An alarm goes off each time medicine is due. Only the compartment of the correct medicine due opens up and can be turned over and the pills dumped right into your hand. Very easy for a legally blind person to feel the open compartment and take their correct medicine with. The dispenser is round in shape. It's well worth it's cost if other methods don't work out.
2nd choice is to place him somewhere until he's fully recovered from the surgery. Again, you find a facility that has a good reputation and very few nosocomial infections (infections acquired at the facility). Where is he regarding being on an antibiotic? He needs a good probiotic to repopulate his gastrointestinal tract to prevent further infections. Infections like C. diff that can be deadly are rampant at some facilities so ask the right questions and look at reviews of the facility online. When you talk to the admitting person of the facility, you go over his needs and that person can tell you what level of care he needs and the estimate of cost.
Then you can consider how much care, if any, he may need once recovered from the surgery and adapting to home life.