Bulimia is a serious issue. You shouldn't be trying to handle it alone, especially as you've been suffering of this for a year and a half already. Many teenagers are suffering from an eating disorder and there are people who are specialized in this area and can help you with this. Please, do get some help before the damages you've been inflicted to your body became too serious. If you can't talk about your eating issue to your parents, you probably can get help at school. Take an appointment with your school counselor or school nurse and let them know about what you're going through. Hopefully, they will be able to help. Take care and let us know how you're doing. (*hug*) Cécile
I definitely have to agree with Cecile. Any eating disorder is very serious. This requires a lot to get over it and change the habit and the feeling of needing to purge. Definitely seek out some help with this, it can't hurt but only help you.
Please take everyone's advice and seek help for your disordered eating. A true resolution to be done with it should result in seeking treatment, not in a binge. Eating one sandwich is fine, and let yourself digest it. Then tell someone about what you've been going through, and see if you can see a specialist. Eating disorders are often about an attempt to have control over your life. It's possible that how you feel about your sexuality is related to your eating disorder, especially since you aren't out to family, so make sure to discuss it in treatment.