I too will get fatigue with GERD. When my doctor first diagnosed me with GERD, he thought it was something else causing my fatigue and doesn't want to believe it's the GERD. I was prescribed Zantac and that has made me feel somewhat better and I don't feel the fatigue as much anymore. Of course, some days are better than others. I've looked at it this way, acid doesn't make us feel good, it makes a lot of us (if not all) feel sick, so in return of feeling sick and full of acid, you're going to lose your energy.