thomas11 I am so sorry to hear about your dad. it's awful to see a family member in very poor health, but so good that you're able to be there for him to confide in, even if the things he needs to say are tough to hear. The fact you're there will mean the world to him.
In regards to the holiday. I did all inclusive Mexico a few years ago and actually found I drank less because it was always there and always available. I was only there for three days for a friend's wedding, but there were so many activities that we could have done had we not been caught up in all the wedding events, so I think you'll find plenty of distraction.
I'm the same as you with food at the moment You'll have plenty of that to enjoy! It's really important to remember that you are NOT missing out on anything by not drinking. I often wake up thinking about the delicious food I had the night before, but I rarely wake up after a night's drinking thinking about how amazing the alcohol was.