Sleeplessness, headaches , nervousness, chest pain, stomach pain, i go from sad to angry to happy in a matter of minutes. what's wrong with me?

Need to see someone: This format isn't the best, but at least it is a start. To know why you are feeling and behaving that way, requires a conversation. There are pieces of information missing and néed to be addressed to draw an accurate possible causes list and then make a plan. I would start by seeing your primary care doctor. Even go to the hospital if you can't be seen today at personal doctor.