Struggling with an Eating Disorder

I was suspected anorexic at the mental hospital I stayed at while they were diagnosing me with other things. I talked my way out of it with excuses like stress causing me stomach problems. They still had a dietitian come in and talk to me and she told me things like I could drink more than 1 soda a day and to try eating cereal for breakfast. I thought this info sounded dumb and didn't take anything she said seriously after that. But I'm basically yoyoing every day looking at myself in the mirror and checking my weight. I always look best in morning and hate how I look at night because of bloat. I eat about 800 calories some days and then binge like 1600 random times days in a row and blow up a few pounds. Im fine with how I look when I'm eating around 1000-1200 calories a day consistently but I read that's still not enough. I really want to like how I look and find it takes priority over my health. I have not mentioned this at all to my therapist and I don't know what is holding me back at this point....but actually I do. I don't have the motivation to change I guess.