What is wrong with me?!

What is wrong with me?

When I stand up for like an hour or so I feel light-headed, i get real dizzy, and tired. My stomach feels sick also. I always immediatley sit down for a few minutes and I will be fine. I started a new job, training horses and I can't just sit down for a couple minutes in the middle of training. My first day was thursday and I was outside for about an hour, It was a bit hot, but not to bad, there was a breeze. While I was leading the horse around I felt tired and sluggish, like i couldn't walk any longer. I must have looked like I was sick also, cuz my boss asked if i was okay. About 15 minutes later we put the horses back in the barn and I still felt sick even after sitting for a bit. I just kinda walked outside and all of the sudden i threw up. It was just water though. I don't know what is wrong with me. I am going to schedule a doctor appt soon. But I am really worried. Plz help. This happens all of the time, even when i am just walking through a store or something. Help plzz

Have you ever paid attention to what you have eaten before you are up, or how long it has been since you ate? There is a condition known as reactive hypoglycemia, that has the symptoms you describe, and it is just a condition where either 1) You haven't eaten in a while and your blood sugar drops too low, or 2) you ate something really high in sugars and then your body produces too much insulin to cover it and them your sugar drops too low. What I would try is to eat several small meals or snacks a day, and keep either crackers, or some small snack with you. When you start feeling bad, try to eat. That may help. Whatever the case you should proibably do as you said and see your doctor.