Eating disorder help

So I started a diet like 4 months ago and it’s a diet where I will usually go 6 days with out eating anything I will just have water and on the 7th day I can eat what I want. Sometimes tho I will just carry on with the water and not have a cheat day sometimes going 3 weeks without any food at all. I’ve lost 4 stone almost and I feel good the hunger has gone and I feel happier than ever but people keep telling me that it isn’t normal for me to be able to go this far without eating and that I have an eating disorder. I mean I don’t think I do because I hate how I look that much I’m willing to do anything to change even if it means not eating like I could eat if I want to I just choose not to because I don’t want to get fat again. Do you think I could have an eating djsorder or not?