26F-I passed out randomly

175lbs/smokes vape
I’ve been depressed and stressed lately . I haven’t been eating 2 days at a time so I’m dropping weight quickly. Haven’t been sleeping well either or sleep all day. Today I was making roux for my gumbo (you have to continually mix the flour & oil for about 30 minutes). While I was standing there with the heat on me. I started getting light headed, seeing stars, my face and fingers were tingling and I threw up whatever I had in my stomach. It’s very rare for me to get sick and throw up. I tried to continue cooking multiple times but the symptoms kept coming back. I had to lay in my bed for a minute to cool down then i passed out for a few hours. I woke up perfectly fine to finish cooking. My stomach is a little sore from throwing up . What can I do to prevent this from happening? I never felt nauseous from cooking before only from heat exhaustion.