I was terrified my bestest bunny friend would hate me once I started T. Rabbits, being prey animals, react much more strongly to changes than dogs and cats do and can be very finicky and skittish. And they do have an incredible sense of smell that they really depend on.
He adores me still. I was so relieved, I'd be completely lost without him. But I do live with him, we share a bedroom. It could take some adjustment if you're away most of the time. Could you maybe go visit your dog every few months in the beginning? Or, if your grandmother is supportive, send her a worn shirt every few weeks for your dog to cuddle with. I've heard of people doing that even when nothing changed except they were going to be away from their pets for an extended period of time.