This is a big problem. You need to try and find help, before this gets any worse. I am not kidding. You know that there’s a problem and you have to do something about it before you die.

1. Yes. Again: yes. Your body doesn’t just need fat. Think of all the vitamins and minerals you’ve been missing with such a drastically decreased food supply.
2. I think that you’re already suffering from malnutrition, at least a little bit. That’s behind a couple of the symptoms you feel.
3. The lines in eating disorders are blurry. Just because you don’t fit exactly into anorexia or bulimia doesn’t mean it can’t be something in between. You have both anorexic and bulimic tendencies, leaning towards anorexia. I know that someone close to me suffers from bulimia, but they restrict what they eat too.
4. Yes, definitely. Weight often has, bizarrely, little to do with anorexia. This is an outlet for your emotional turmoil, not a diet. You definitely are anorexic, even if you weigh two hundred pounds, let alone one hundred ten.
5.113-152. I used a BMI calculator, in the sources, to check this.
6. You are in danger both physically and emotionally. Physically, your danger comes from a possible nutrient deficiency, or alternately, different forms of malnutrition and weakness. Emotionally, you are in danger because your mind is unstable after what you’ve gone through. You can’t cope with things anymore because of what’s happened. You need control. So you control the only thing you feel like you almost can, and obsessively: your weight. This is very dangerous for many reasons. You could harm yourself by sinking deeper, or even commit *******.
6. Again, because this isn’t a physical problem. This is something that can’t stress enough. Your mind is changed by what you went through. It’s a mental block, if you will.