One thing I have used at christmas time in the past is to start making a pattern of breaks for yourself. In my case I am a gardener, and many years ago I began my tradition of walking round my garden first one way and then the other, and noting any plants flowering , showing shoots etc, and I do the same on New Years Day. These have actually been useful as I lived in one place for 20 years, so it was the same garden all that time. The RHS asked gardeners to give their earliest dates for flowering to help to see what change there was in the climate etc. But that was not the importance of it. The plan was to have this "escape" route available to me at any time during the day, so when things were getting fraught, or something was burnt or whatever, I would announce that I was just going to do my check round the garden, and escape with secateurs in hand!! That allowed me to both calm down, take a deep breath, but at the same time do quite a bit of savage snipping with the secateurs!! Found this very therapeutic, and the family got used to my disappearing out every so often. Perhaps you could do something similar, even if it has to be blaming an upset stomach and disappearing to the bathroom for a few minutes to calm down. Having that little escape place arranged might let you feel a little more in charge of your own time if not your parents. The other thing is that of course you are just seeing them at their worst , because you have just come into the scenario. I dont say that they like it , but it could be normal for the way they now live and they do not see it as so bad. Then could you think of a couple of different things that they each like, so that you would have the opportunity to spend time with one of them on their own, whether perhaps baking or doing a jigsaw or playing cards. whatever you can think of that the other parent would not want to join in with. At least that would also give you and them a breathing space. Also if you are a driver , dont forget the possibility to have a short drive to somewhere either they like , or suggest a drive to see some places you havent seen for a while. Often people are quieter and calmer especially if you have one in the front and one in the back. Doesnt actually matter if they look out of the window, shut their eyes or read a paper, you will probably get a bit of peace whilst you are out. Dont forget when you shut the bedroom door you can also give the pillow a good punch or two to relieve feelings. Wishing you the best you can manage and whereas the children count down to christmas day, you can count down to the 12 days of christmas and the way home.