Posted this earlier in your original thread but will repeat here too.
You are clearly loved and appreciated at your place of work, it is not that way for most people. And although it is not very understanding of them to put this on you, they have put a lot of effort into this, for you. It is just one day, the next morning it will be all over. It will be hard, been the centre of attention, inwardly your going to be terrified, but you can fake surprise so you can paint a face on and get through this. Take a moment to just be alone if things get overwhelming even if that means just popping to the gents. And try and put a positive spin on it, you could learn and grow from this, just like with all life experiences. You are loved at work and your hard work is been celebrated by others, that's a wonderful thing, embrace it.