From last 6,7 days my stomach is disturbed. feel of burning, little nausea, sometimes unable to burp, etc. i only eat home cooked food, fruits daily, and drink a lot of water. i wake up whole night and sleep after breakfast. what could be the reason?

Symptoms is likely due to a stomach problem, dyspepsia vs early symptoms of peptic ulcer disease, less likely a viral or bacterial illness. I suggest to try antacid such as maalox or mylanta or any generic antacid, 2 tablespoons before meals and at bedtime for a couple days. If symptoms do not resolve by next week, you can see your doctor by then.