I'm coming home extremely exhausted. Need advice.

I am attending training sesssion where I am taught about various team building exercises, public speaking, and a bunch of other stuff too. Most of the people are around my age and my seniors who have done this training before have advised me to volunteer in the exercises and speak often. The duration of each session everday is 8 hours and we are a group of 50 people.

I am following their advice. People there are nice and kind. I am enjoying my time there as I have done public speaking in my school and college so it is great to do it again but I overpush my energy with constant smile and talking to others. I don't hate them but I am not used to socialising at a much larger scale. Moreover during recess, people talk among themselves and the sound gets too loud which makes me very overwhelmed.

When I come back home, I am too exhausted to do anything. At first I assumed it was because I am not used to it but even after 10 days have passed, I am still exhausted and I have no energy to prepare my own food (I don't like takeouts) or do any other work that I have on my schedule. Any advice that can help me to not be exhausted?