Wow I've never heard of a doctor doing something so extreme for poorly controlled blood sugars. In his mind, he must feel that your father is in someway abusing you or preventing you from taking your meds, etc... I'm sorry he has done that. And not knowing the whole story I don't know where his justification is.
Being a teenager with diabetes is extremely hard for multiple reasons. First your hormones change your insulin needs, your sensitivity, etc... Second, is the social part. It's difficult enough to steer away from the alcholol, drugs, etc... that staying conscience of every piece of food that goes in your mouth seems almost impossible - although it is not. I feel for you and I personally am glad that I have outgrown that difficult part of my life. My advice to you is, if possible, get a doctor that you like. There are physicians out there that aren't total idiots. I'm hoping that your dad or another adult can help you find someone that will listen to you. These few years are the hardest and most challenging. You've accomplished a lot if you can get a good grip of your diabetes during this time before the diabetes gets a grip on you.
Again, I'm so sorry you and your father are going through this and we are here to listen and help you out as much as possible.