Hey Sarah,
That sounds like a horrible situation to be in because it feels like you're having to choose between two people you love, even though you really don't want to. Having been there with my own family, I know it can be super hard.
I'm not sure what the situation is at home but it sounds like your father can be a bit of a loose cannon.
Perhaps it's easier to think of it as: you won't really have control over what happens, but you can at least mentally prepare yourself. Whatever your father chooses to say or do is going to probably come from a place of misunderstanding, but not out of lack of love for you. It's important to remember that it'll be anger and frustration, but not hatred.
If it was me, I'd probably actually tell him in person. It'll be a bit of a blow for him to receive it at work. Better be told at his own place away from the stress of work.
That said, the situation might be that you don't feel like you can do it in person. I suppose you're the best judge of that.
I don't know. Family things are really hard, but you can hold onto the love that will still continue to exist, even if he does blow up.
James
