Regardless of how horrible you're feeling, (I'm sorry, I know that sounds callous but my answer is in context of the question), you have said that the holiday is booked in his name so I'm afraid it doesn't sound like you're going so perhaps you could try and find something else relaxing and diverting to do with the time. The rest of the horrible feeling stuff I'm afraid you just have to muddle through and time will generally help that which unfortunately is a cliche but also true.