Is he getting you any help with all of that? I've had an eating disorder most of my life, and was at a dangerously low weight throughout most of high school and my dad's solution was always "what do we need to do to get you to gain some weight". It took child protective services being called and a lot more drama before I ever got real treatment. I don't think he meant not to help, he just didn't know better. I think a lot of the time, parents, especially dad's. don't want to see something, so they don't, but the problem is still there. Food is never really the true issue. Weight is never really the core issue. If your weight is that low, you probably need some pretty intensive treatment and really should be under a doctor's supervision.
Can you talk to him about at least seeing your doctor and seeing where they take it from there?