hunni, you need to get some help. i've been there before and it's no fun. 89 pounds is a healthy weight if, say, you're 4'8" or so. otherwise, nope.
binging, purging, starving yourself, all have so many side effects, i mean there's the obvious ones, like the dental work being permanent (and made worse if you have braces). but you can do yourself nerve damage with anorexia, and if you purge often enough what can happen is that your oesophagus can split open because all the stomach acid has worn it down. it's not exactly nice.
i understand how you want control, but after a while, as great as it may be at the start, you truly do lose control and all you hear is ana or mia in your head.
please please please, go and get some help.
TDM