Haha! You are literally me a few mins ago..I wrote out a panic post I didnt finish cos there was an incident that happened about 30 mins ago, except mine was more "fear" than excitement as I thought I heard someone downstairs in the dark so my tummy must have turned and immediately I got the sick throat for the first time in AAAAGES. Awful. Only just started to calm down... yours will definitely be the excitement, you have answered your own question I think haha.
If you wanna crash from the anxiety, try putting some meditation music on, Im listening to one now on youtube in the dark, its helping