Thanks everyone for the suggestions
I never thought that my training regime is that heavy, until you guys pointed out. I used to train 10 hours aikido/week, but the 7 hours of dance are a new addition. Never thought of it as something physically taxing, but it is.
Always been a meat lover and hater of veggie. But yesterday I followed your advice and went to an university restaurant (I'm in Paris btw). Here the portion and diet is fixed for everyone, so no pick and choose. I got a plate of green beans, carrot, potatoes and fried fish. Amazing, the portion looks small but it fills me up way better than my usual meat-only diet. And I also feel much more energized today.
I'll work on changing my diet right away with this discovery.