Lately i've been having nausea, frequent bowel movements that are greenish, and a burning pain around the belly button, it happens in the morning.

GI issue: Sounds like an issue with your intestinal tract. See your doc and get a work-up as necessary.

Try an antacid: Greenish stool is not a problem. Black colored stools would suggest bleeding ulcer. Your symptoms seem to be from a stomach (gastric) acid problem, so you can try an over the counter antacid. If you're not better by 2 days, then see a clinician to get evaluated & treated. Hope that helps.