What to do if i do not eat very much and when i do i make myself throw up. if i throw up a lot can i throw up parts of my stomach?

Induced Vomiting: You can not throw up parts of your stomach but you can end up with a small tear in your esophagus in which case you may see blood. It is generally not a good idea to induce vomiting. If you are not eating because you are frequently nauseous then you need to be evaluated.

Eating disorder: Seek treatment immediately. You will not throw up parts of your stomach but will cause a number of serious health problems including esophageal tears, tooth damage, hair loss, and a wide variety of problems caused by nutrient deficiencies, including emotional disturbances.