Hey, yes it does sound like you have an eating disorder because of the fact that you are intentionally not eating as much as you probably should be. I think that if you tell your therapist again, maybe they might take it more seriously this time because you've already brought it up before. I'm sorry to hear that you aren't pleased with your weight but considering the feedback you get from others, that doesn't really matter to people. If you'd like to lose weight, maybe you should just eat on a regular schedule but workout on a daily basis as well? That's all the advice I have for now, hopefully that was helpful.
Pm me anytime if you'd like to talk!
-Jessica