I wouldn't fly home. It's your break away as well.
I would be fucking furious he waited until the first day of a holiday far from support network to blurt this out.
So you come away he gets this all off his chest and you are left bewildered at what's just hit you with the whole of the holiday to go? Yes I would be furious.
But not to let time off work, presuming sunshine, what's around? Does hotel have a pool?
You need to recharge OP for return home.
So what can you do? What do you need? (Him aside)
Do you need sunshine, exercise, feed your culture, pool, book, spa day, coffee people watching, practice a language, good food?
Go and seek some of that out, leave him alone, get some space.
Nothing you can do about your relationship right now, don't talk about it, park it for return home, by all means message a friend, just don't talk to him about it.
Let him find something to do alone, he caused all this.
Any day trips you fancy?