Yes, to put it bluntly. No matter how little or often you do it, or when you do it, it can cause serious health problems.
Sweetheart, I'd advise you try to get out of this. I understand the feeling of control, but its not good. It can lead to a lot of health problems, rotting teeth, kidney issues, lack of vitamins...its generally a very very bad route to go down.
Weight isn't so much an issue with bulimia - one of the classifications is that they're generally normal weight, or a tad overweight.
To warn you, don't brush teeth directly after throwing up, as it won't help. You're just brushing the acid into your teeth. Leave it a couple of hours.
Take care of yourself, please. Go to your doctor, and basically say what you have said here.
If you ever want to PM me, thats fine. Look after you. Jo xx