Kaily, you’ve a lot to deal with and your dad not seeming to want you on the journey isn’t helping you. You’re doing the best that you can for him, but you know how stubborn us humans can be, especially If we feel our independence is going from us.
Has he been given instructions what happens if he has a cardiac arrest at any time. The device will help but what about what he does then. He should have something from the hospital which may put your mind at rest too.
Take care and remember to breathe.