Since I started highschool I've been having this problem, it seems like it's from my back.. But it's not just my back...it's multiple things. This normally starts after I eat something or after standing up for a very short period of time. I'm 5'4 and 115 lbs. It starts off like this: my whole body starts to feel heavy and weak, my back hurts (not sharp pain though) it's like that feeling of standing up for a long time, I feel short of breath and like I'm not getting enough oxygen. I start to sweat and feel hot and faint. I may start slightly shaking. This also happens when Im around large groups of people but I think that is just anxiety....I don't know if that's related. Some things that might be signs: I bruise kinda easily, it's dark under my eyes (been like that since the problem started), I'm always thirsty but I drink a good amount of water, I have flat feet (may cause the back pain?), my flat feet cause me to have issues with my legs and knees especially. Please help. The doctor I go to seems incompetent to me. He just says that I need to wear dr. Schols and that it will fix everything. I am now a junior and I have been wearing those stupid things for 3 or 4 years now and they don't do squat. Please help ):