What Causes Dizziness And Weakness While Suffering From Flu?

I ve gotten the flu about 2 weeks ago, but it feels as if now it could be worse. Iv been so weak, i can hardly get out of bed to go the bathroom, because its so hard to breath and weak and dizzy. My head has been feeling as if its in a cloud, and confused about things terribly and having trouble rembering things. Im not taking any medicines , so i dont know why im feeling weird in my head, its almost as if, i cant hardly think anything. But my head isnt the worst part, its me being terriblely weak and cant hardly breath, that scares me the most. Ive lost my appetite, but when i do eat, i feel like throwing up. Ive got diarea, and when i try to sit up, i feel a heaviness on my chest and can feel like there maybe fluid building up n my lungs. And ive noticed just recently, im not coafing since this past week but ive noticed a lot of spit keeps building up and when i spit, its like a dark, brownish red color...what do u think could be going on?