Major mood changes and not sleeping. Do they sound like serious signs?

Get checked. Mood changes and sleep issues could be sings of many problems. Talk to your primary care provider to help you rule out anything medical going on. Also, have there been any changes in your life, routine? Work on sleep hygiene and keep a diary to record your moods to find triggers of moodiness. Find a counselor to help you guide through the process. Medication evaluation with psych if needed.