Going away on holiday is something to enjoy. However, most of us wont allow ourselves to enjoy anything because we keep the loop of anxious thoughts rolling round. This is, I think, the key. If you can force yourself to just concentrate on having a good time, and try and treat every moment you can of the vacation as a vaction from DP/DR, maybe it'll go a little easier.
I just got back from my Grandparents this evening. I'm doing better lately, so it was mostly OK apart from when I was tired and the huge amount of spiders there were in the cottage we stayed in while not at my Grandparents house. However, on the way back home I convinced myself that the walls of the houses I was passing looked bleached out in colour (it was probably just the sun shining on them, but I was thinking it was a problem with my eyes!). I got home, and went to my room, and things didn't look right. I could see a physical mist in the air, but I'm sure it wasn't really there. The whole house seemed alien after just 4 days away. What could I do? I sunk myself into surfing the net. Now, things seem more like usual (although not normal, obviously, I've had DR 24-7 for 2.5 years now
) I've stopped the worrying about it, and it's got better.
I hope it goes well for you, just try to enjoy it.