What a beautiful cat!
I would say to just give it time. It took the yorkies a while to learn that the cats weren't made to be chased around and tortured. Eventually, they all learned how much of each other they could stand, and there were no problems.
We kept the litterbox in the basement, where the dogs were never allowed to go. If you could, I'd probably try to keep free feeding him. Put him on some kind of weight-control food, and put his bowl in a place where Layla can't get to it. Its just that we had a....kind of....fat cat haha, and he was so used to being free fed that if there ever wasn't food in his bowl or whatever he would get SO stressed out that he'd shed like mad and he wouldn't sleep. So I think letting him free feed would help keep the stress level down, as long as he's on healthier food.
Prayers that your exam will go well tomorrow!
Best of luck with everything! This is a great thing you're doing!