Things I cannot go without on holiday

I love going on a holiday, far away from the daily crap that goes on here. Preferably with more sunshine, great views, wonderful cities, fun people and good food. This year I'm going to Budapest and I will spend 16 days there. I'm going with 3 people I could consider friends, though I barely know them. So this holiday could go either good or bad. I do believe that it's not only up to me to make it a success, but I also believe that things are as fun as you make them. But I do have a few essentials to make any holiday a great success for me and I will put those in a list below.

Negative vs Positive

When 9 out of 10 times you think negative thoughts, you barely notice you're dragging yourself down. When in your eyes everything you do is either not special on exciting life gets boring and just a drag.
And every time something goes wrong or things don't go the way they were supposed to you think it's because of you. Yes, at that point you actually believe you are worthless. And the positive things that happen to you are barely noticeable. What to do?