Since you are 16, there isn't a whole lot you can do since you are still a minor, but you have a few options. The best thing to do is probably to find your local SRS and they can give you information and support. They see stuff like this all the time.
I can see why she would be upset, because you are her responsibility, but not your baby, but you can't really separate the two. Having a baby is for adults to do, so technically you should be doing everything else that an adult does, and quite frankly, you can't because you aren't old enough. It's hard for me to say exactly what the scenario should be here because I don't know what your family ground rules are.
You also have the option of making your boyfriend help you out. He IS the father and an adult, so he is going to have to provide some support to you and the baby.
Good luck.