Male 20s. when i eat carbohydrates, i cannot think properly, i get bloated, my nipples get extremely puffy, and i feel exhausted. when i eat a high protein and fat diet i feel much better. what is going on with me? the last year i have had this?

Your body is talking to you. Listen and take good notes, Then share with your health care team. As an old Dr told me long ago when I said "doing Y makes me feel bad". He told me, "Don't do Y". Still good advice till you figure out what is going on.

Would strongly urge that this be evaluated, preferably by an internist. Possible explanations include gluten sensitivity secondary to Celiac disease, potential blood sugar variations, etc. To get this clarified, make an appointment ASAP. Do heed Dr Grim's advice for the time being.