Oh dear! Rachel, do you consider yourself to be an Empath by any chance? Even if it’s not something that usually resonates with you, being in such a crowded, high-energy, high-excitement situation for multiple days can have a huge impact on anyone’s energy. It sounds like you may have picked up and even unwilling taken on the moods and emotions of those around you- and that can indeed be exhausting! 
For now, I would recommend focusing on Self-Care Work to help both your body and mind relax, refresh, and recover. Going forward, you can help to protect your energy in such situations by using Empath Shielding (tips on energy shielding here and empath shielding spray here) in addition to any Protection Spells that focus on energy defense 
Get some good rest and I hope that you are feeling much better soon, Rachel! Blessed be 