I Have Recently Been A Light Headed, I Have A

I have recently been a light headed, I have a loss in appetite and a lost in thirst, sometimes I get lower abdomen pain, headaches occur sudden in the middle of the forehead, and for a couple of days sudden vomiting occurs. Even if I feel fine, just like someone would do if they was pregnant, but there's no possible way that could happen because I don't date guys. I woke up not too long ago with discoloration on my right arm and hand. I'm a 20 year old female.