Hi I'm 18 Years Old Female And Never Had Regular

Hi I'm 18 years old female and never had regular bowel movements but about 2 weeks ago I couldnt sleep at night due to nausea, vomiting, diarrhoea and constipation and I am suffering from nausea and strange pain in my lower abdominal. I definitely don't have the healthiest diet in the world and I'm sure that's part of the problem but do you think I should see a doctor about this? My mom is a nurse and she keeps brushing it off saying it's diet related but I'm not so sure. Any advice on what to do would be brilliant! Thank you