My dad won't go to the hospital! What can I do?

My dad has several illness due to him neglecting his health for several years (eating junk, not exercising at all) despite my pleas. He's been in hospital 5 times in 3 years. Most recently, He was in the hospital then a rehab home for awhile, but left early so he wouldn't lose his job even though he could only take a few steps at a time. He's been out of the rehab home for about three weeks now, but his health has deteriorated. He cannot walk at all, can't sit up in bed, can't even roll over. He's 300 pounds and I'm hurting myself by trying to lift and move him around. He can't even make it to the bathroom. I've been washing him, emptying his urine bottles, feeding him according to the 3 different special diets he's on, and giving him his 13 prescriptions 24/7. I'm doing the best I can, but his room is downright unsanitary because I can't keep up. I can't leave the house because I can't leave him alone. To make matters worse, he has many phobias, anxiety, and mental health issues that make caring for him almost unbearable. He's generally ungrateful and demanding. Now hes wearing diapers and wants me to change him when he poos. I can't take it anymore! I told him he needs to go back to the hospital so they can find out what's wrong and care for him properly, but he said we won't go. I simply don't have strength or the energy to do this alone. Is there anyway I can make them take him? What do I do?