SO's Health

Brittany • Mommy to a wonderful 12yr old boy, 9yr old boy 7yr old girl 6yr old girl and 3yr old girl. Due March 11th 2023 with a boy.
My SO and father to our 3 children is 330lbs at 5'10". He has high blood pressure and has for a long time. He recently went to the hospital for kidney stones and was told by his work that he needs a release to go back to work cuz they took him off form2 days. He went to prompt care and they refused to release him back to work because of his blood pressure. It's so high that he's at risk for a stroke. He takes medication for it, but he forgets sometimes and it's not working properly. I don't know what to do to motivate him to loose weight. I could threaten to leave but what good would that do. I tell him our kids need a father more than they need a check from the state. He says that he is invincible and is going to live forever. He's 29 and acting like a damn child. I need him and my kids need him. What can I do? I'm so broken over the thought of loosing him.