cat, I think the answer can be found from your own words "i would have a small banana & a bit of a biscuit but after havin eat them i will feel realy sick all day & hate my self 4 havein eaten any thing at all"
I think that qualifies as a disorder.
What does your husband think? Does he make comments about your weight?
I bet he thinks you're just fine the way you are!
If you focus on the many good qualities about you and your life, you will come to find you mean a lot more to people than how much you weigh. Develop the real, inner "you" and the weight problem will go away.