Rescue Remedy +1
I’m a fairly anxious person - my parents are both jangly, especially my mother. I get a mix of the two. I tend to do the following:
• If I am planning something, or trying something new I *have* to see in my mind what is going to happen and how it should work.
• When things are just about ready to go, my natural pessimism kicks in, and at this point I get anxious.
So, I understand anxiety, especially for something which is a one off special event. Things will go well - even if it does not go exactly according to plan, your parents will love it, and it will mean a lot to them that you did it.
Try to relax (I know, easier said than down), and get some Rescue Remedy. Boots stock it.