When singing my voice is gone for a few days. Why?

I've been playing guitar and singing since 8th grade and i'm 23 now. I've never had a problem until after I graduated high school. I had an acid reflux problem at college because of drinking, I seldom drink now. I'm a gym junkie and drink over a gallon of water a day. I try to play and record songs but I cannot because after the first song my voice is shot, the low notes make me cough and the high notes are just air. The only thing i can do is falsetto for higher pitches and the lower pitches are gone. For the 3 weeks, my voice has been hoarse from drinking a lot during the holiday and I'm guessing that could damage them for a little, but either I'm getting my reflux back from God knows what or i've permanently damaged my voice. I just tried singing and I couldn't make it half through the first chorus before my voice was worse than before I started. Honey, tea, all that good stuff does not do anything for me. I've gone to voice coaches before, I've had scopes done to my throat, just looks red and irritated from the screen I was looking at. If you ask me this is bullshit, I won't sing, go out, or do anything for a month and my voice will still be gone in no time. The last thing I can conclude is, when lifting weights I lift hard, I'm intense. That being said, I think I breathe extremely heavy every set where I'm dizzy when i get up, Could this also damage my voice?